Moving lightning_api_access out of base requirements (#15844)

* moving the requirements to components extras

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* component requirements to devel

* importing torch in local scope

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* skipping doctest

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Jirka <jirka.borovec@seznam.cz>
Co-authored-by: Jirka Borovec <6035284+Borda@users.noreply.github.com>

requirements/app/base.txt

@@ -12,4 +12,3 @@ beautifulsoup4>=4.8.0, <4.11.2
 inquirer>=2.10.0
 psutil<5.9.4
 click<=8.1.3
-lightning_api_access>=0.0.3

requirements/app/components.txt

@@ -0,0 +1,2 @@
+# deps required by components in the lightning app repository (src/lightning_app/components)
+lightning_api_access>=0.0.3

requirements/app/devel.txt

@@ -10,4 +10,7 @@
 # extended list of dependencies for UI
 -r ./ui.txt
 
+# extended list of dependencies for UI
+-r ./components.txt
+
 -r ./examples.txt

src/lightning_app/components/serve/python_server.py

@@ -6,6 +6,7 @@
 
 import uvicorn
 from fastapi import FastAPI
+from lightning_utilities.core.imports import module_available
 from pydantic import BaseModel
 from starlette.staticfiles import StaticFiles
 
@@ -17,9 +18,14 @@
 
 logger = Logger(__name__)
 
+__doctest_skip__ = []
+# Skip doctests if requirements aren't available
+if not module_available("lightning_api_access"):
+    __doctest_skip__ += ["PythonServer", "PythonServer.*"]
+
 # Skip doctests if requirements aren't available
 if not _is_torch_available():
-    __doctest_skip__ = ["PythonServer", "PythonServer.*"]
+    __doctest_skip__ += ["PythonServer", "PythonServer.*"]
 
 
 class _PyTorchSpawnRunExecutor(WorkRunExecutor):
@@ -90,7 +96,7 @@ def _get_sample_data() -> Dict[Any, Any]:
 
 
 class PythonServer(LightningWork, abc.ABC):
-    @requires("torch")
+    @requires(["torch", "lightning_api_access"])
     def __init__(  # type: ignore
         self,
         host: str = "127.0.0.1",