Remove references to ConcurrentTaskRunner from docs and ensure exam…

…ples use `.wait()` (#14144)

Co-authored-by: Bill Palombi <bill@prefect.io>

docs/2.19.x/concepts/task-runners.mdx

@@ -1,5 +1,5 @@
 ---
-title: task Runners
+title: Task runners
 description: Task runners enable you to engage specific executors for Prefect tasks, such as for concurrent, parallel, or distributed execution of tasks.
 ---
 

docs/3.0rc/develop/write-flows/index.mdx

@@ -409,7 +409,7 @@ Flows allow a great deal of configuration by passing arguments to the decorator.
 | `retries`                                          | An optional number of times to retry on flow run failure.                                                                                                                                                            |
 | <span class="no-wrap">`retry_delay_seconds`</span> | An optional number of seconds to wait before retrying the flow after failure. This is only applicable if `retries` is nonzero.                                                                                       |
 | `flow_run_name`                                    | An optional name to distinguish runs of this flow; this name can be provided as a string template with the flow's parameters as variables; you can also provide this name as a function that returns a string.       |
-| `task_runner`                                      | An optional [task runner](/3.0rc/develop/write-tasks/use-task-runners/) to use for task execution within the flow when you `.submit()` tasks. If not provided and you `.submit()` tasks, the `ConcurrentTaskRunner` is used.         |
+| `task_runner`                                      | An optional [task runner](/3.0rc/develop/write-tasks/use-task-runners/) to use for task execution within the flow when you `.submit()` tasks. If not provided and you `.submit()` tasks, the `ThreadPoolTaskRunner` is used.         |
 | `timeout_seconds`                                  | An optional number of seconds indicating a maximum runtime for the flow. If the flow exceeds this runtime, it is marked as failed. Flow execution may continue until the next task is called.                   |
 | `validate_parameters`                              | Boolean indicating whether parameters passed to flows are validated by Pydantic. Default is `True`.                                                                                                                  |
 | `version`                                          | An optional version string for the flow. If not provided, we will attempt to create a version string as a hash of the file containing the wrapped function. If the file cannot be located, the version will be null. |
@@ -600,7 +600,6 @@ Running the `hello_world()` flow (in this example from the file `hello.py`) crea
 ```bash
 $ python hello.py
 15:19:21.651 | INFO    | prefect.engine - Created flow run 'daft-cougar' for flow 'Hello Flow'
-15:19:21.651 | INFO    | Flow run 'daft-cougar' - Using task runner 'ConcurrentTaskRunner'
 15:19:21.945 | INFO    | Flow run 'daft-cougar' - Created task run 'Print Hello-84f0fe0e-0' for task 'Print Hello'
 Hello Marvin!
 15:19:22.055 | INFO    | Task run 'Print Hello-84f0fe0e-0' - Finished in state Completed()
@@ -676,7 +675,6 @@ Running this flow produces the following result:
 <div class="terminal">
 ```bash
 22:22:36.864 | INFO    | prefect.engine - Created flow run 'acrid-tuatara' for flow 'always-fails-flow'
-22:22:36.864 | INFO    | Flow run 'acrid-tuatara' - Starting 'ConcurrentTaskRunner'; submitted tasks will be run concurrently...
 22:22:37.060 | ERROR   | Flow run 'acrid-tuatara' - Encountered exception during execution:
 Traceback (most recent call last):...
 ValueError: This flow immediately fails
@@ -713,7 +711,6 @@ Running this flow produces the following result:
 <div class="terminal">
 ```bash
 18:32:05.345 | INFO    | prefect.engine - Created flow run 'auburn-lionfish' for flow 'always-fails-flow'
-18:32:05.346 | INFO    | Flow run 'auburn-lionfish' - Starting 'ConcurrentTaskRunner'; submitted tasks will be run concurrently...
 18:32:05.582 | INFO    | Flow run 'auburn-lionfish' - Created task run 'always_fails_task-96e4be14-0' for task 'always_fails_task'
 18:32:05.582 | INFO    | Flow run 'auburn-lionfish' - Submitted task run 'always_fails_task-96e4be14-0' for execution.
 18:32:05.610 | ERROR   | Task run 'always_fails_task-96e4be14-0' - Encountered exception during execution:
@@ -763,7 +760,6 @@ Running this flow produces the following result&mdash;it succeeds because it ret
 <div class="terminal">
 ```bash
 18:35:24.965 | INFO    | prefect.engine - Created flow run 'whispering-guan' for flow 'always-succeeds-flow'
-18:35:24.965 | INFO    | Flow run 'whispering-guan' - Starting 'ConcurrentTaskRunner'; submitted tasks will be run concurrently...
 18:35:25.204 | INFO    | Flow run 'whispering-guan' - Created task run 'always_fails_task-96e4be14-0' for task 'always_fails_task'
 18:35:25.205 | INFO    | Flow run 'whispering-guan' - Submitted task run 'always_fails_task-96e4be14-0' for execution.
 18:35:25.232 | ERROR   | Task run 'always_fails_task-96e4be14-0' - Encountered exception during execution:
@@ -814,7 +810,6 @@ Note that the final state is `Failed`, but the states of each of the returned fu
 <div class="terminal">
 ```bash
 20:57:51.547 | INFO    | prefect.engine - Created flow run 'impartial-gorilla' for flow 'always-fails-flow'
-20:57:51.548 | INFO    | Flow run 'impartial-gorilla' - Using task runner 'ConcurrentTaskRunner'
 20:57:51.645 | INFO    | Flow run 'impartial-gorilla' - Created task run 'always_fails_task-58ea43a6-0' for task 'always_fails_task'
 20:57:51.686 | INFO    | Flow run 'impartial-gorilla' - Created task run 'always_succeeds_task-c9014725-0' for task 'always_succeeds_task'
 20:57:51.727 | ERROR   | Task run 'always_fails_task-58ea43a6-0' - Encountered exception during execution:
@@ -870,7 +865,6 @@ Running this flow produces the following result.
 <div class="terminal">
 ```bash
 18:37:42.844 | INFO    | prefect.engine - Created flow run 'lavender-elk' for flow 'always-succeeds-flow'
-18:37:42.845 | INFO    | Flow run 'lavender-elk' - Starting 'ConcurrentTaskRunner'; submitted tasks will be run concurrently...
 18:37:43.125 | INFO    | Flow run 'lavender-elk' - Created task run 'always_fails_task-96e4be14-0' for task 'always_fails_task'
 18:37:43.126 | INFO    | Flow run 'lavender-elk' - Submitted task run 'always_fails_task-96e4be14-0' for execution.
 18:37:43.162 | INFO    | Flow run 'lavender-elk' - Created task run 'always_succeeds_task-9c27db32-0' for task 'always_succeeds_task'
@@ -911,7 +905,6 @@ Running this flow produces the following result.
 <div class="terminal">
 ```bash
 21:02:45.715 | INFO    | prefect.engine - Created flow run 'sparkling-pony' for flow 'always-succeeds-flow'
-21:02:45.715 | INFO    | Flow run 'sparkling-pony' - Using task runner 'ConcurrentTaskRunner'
 21:02:45.816 | INFO    | Flow run 'sparkling-pony' - Created task run 'always_fails_task-58ea43a6-0' for task 'always_fails_task'
 21:02:45.853 | ERROR   | Task run 'always_fails_task-58ea43a6-0' - Encountered exception during execution:
 Traceback (most recent call last):...

docs/3.0rc/develop/write-tasks/dask-and-ray.mdx

@@ -318,7 +318,7 @@ Many workflows include a variety of tasks, and not all of them benefit from para
 Because task runners are specified on flows, you can assign different task runners to tasks by using
 [subflows](/3.0rc/develop/write-flows/#composing-flows) to organize those tasks.
 
-This example uses the default `ConcurrentTaskRunner`. Then you call a `ray_greetings()` subflow that
+This example uses the default `ThreadPoolTaskRunner`. Then you call a `ray_greetings()` subflow that
 uses the `RayTaskRunner` to execute the same tasks in a Ray instance.
 
 ```python

docs/3.0rc/develop/write-tasks/use-task-runners.mdx

@@ -21,10 +21,8 @@ which runs tasks concurrently within a thread pool.
 The following Prefect-developed task runners for parallel or distributed task 
 execution are available as [integrations](/integrations/catalog/):
 
-- [`DaskTaskRunner`](https://prefecthq.github.io/prefect-dask/) can run tasks using 
-[`dask.distributed`](http://distributed.dask.org/). 
-- [`RayTaskRunner`](https://prefecthq.github.io/prefect-ray/) can run tasks using 
-[Ray](https://www.ray.io/).
+- [`DaskTaskRunner`](https://github.com/PrefectHQ/prefect/tree/main/src/integrations/prefect-dask) can run tasks using [`dask.distributed`](http://distributed.dask.org/).
+- [`RayTaskRunner`](https://github.com/PrefectHQ/prefect/tree/main/src/integrations/prefect-ray) can run tasks using [Ray](https://www.ray.io/).
 
 <Note>
 **Concurrency vs. parallelism**
@@ -208,7 +206,7 @@ def my_task():
 def my_flow():
     future = my_task.submit()
     result = future.result(raise_on_failure=False)
-    if future.get_state().is_failed():
+    if future.state.is_failed():
         # `result` is an exception! handle accordingly
         ...
     else:

src/prefect/flows.py

@@ -147,7 +147,7 @@ class Flow(Generic[P, R]):
             be provided as a string template with the flow's parameters as variables,
             or a function that returns a string.
         task_runner: An optional task runner to use for task execution within the flow;
-            if not provided, a `ConcurrentTaskRunner` will be used.
+            if not provided, a `ThreadPoolTaskRunner` will be used.
         description: An optional string description for the flow; if not provided, the
             description will be pulled from the docstring for the decorated function.
         timeout_seconds: An optional number of seconds indicating a maximum runtime for