Remove quantum engine sampler (#5673)

* Minor updates to development page

- Change Foxtail to Sycamore since Foxtail is deprecated.
- Add some clarification that instructions are for linux.

* Remove deprecated QuantumEngineSampler

cirq-google/cirq_google/__init__.py

@@ -74,7 +74,6 @@
     EngineProcessor,
     EngineResult,
     ProtoVersion,
-    QuantumEngineSampler,
     ProcessorSampler,
     ValidatingSampler,
     get_engine,

cirq-google/cirq_google/calibration/phased_fsim.py

@@ -544,7 +544,7 @@ class LocalXEBPhasedFSimCalibrationOptions(XEBPhasedFSimCalibrationOptions):
     These "Local" options (corresponding to `LocalXEBPhasedFSimCalibrationRequest`) instruct
     `cirq_google.run_calibrations` to execute XEB analysis locally (not via the quantum
     engine). As such, `run_calibrations` can work with any `cirq.Sampler`, not just
-    `QuantumEngineSampler`.
+    `ProcessorSampler`.
 
     Args:
         n_library_circuits: The number of distinct, two-qubit random circuits to use in our
@@ -864,7 +864,7 @@ class LocalXEBPhasedFSimCalibrationRequest(PhasedFSimCalibrationRequest):
     A "Local" request (corresponding to `LocalXEBPhasedFSimCalibrationOptions`) instructs
     `cirq_google.run_calibrations` to execute XEB analysis locally (not via the quantum
     engine). As such, `run_calibrations` can work with any `cirq.Sampler`, not just
-    `QuantumEngineSampler`.
+    `ProcessorSampler`.
 
     Attributes:
         options: local-XEB-specific characterization options.

cirq-google/cirq_google/engine/__init__.py

@@ -67,8 +67,6 @@
     estimate_run_sweep_time,
 )
 
-from cirq_google.engine.engine_sampler import QuantumEngineSampler
-
 from cirq_google.engine.validating_sampler import ValidatingSampler
 
 from cirq_google.engine.virtual_engine_factory import (

cirq-google/cirq_google/engine/engine.py

@@ -763,7 +763,7 @@ def sampler(self, processor_id: Union[str, List[str]]) -> 'cirq_google.Processor
                 determining which processors may be used when sampling.
 
         Returns:
-            A `cirq.Sampler` instance (specifically a `engine_sampler.QuantumEngineSampler`
+            A `cirq.Sampler` instance (specifically a `engine_sampler.ProcessorSampler`
             that will send circuits to the Quantum Computing Service
             when sampled.
         """
@@ -776,7 +776,7 @@ def get_sampler(self, processor_id: Union[str, List[str]]) -> 'cirq_google.Proce
             processor_id: String identifier of which processor should be used to sample.
 
         Returns:
-            A `cirq.Sampler` instance (specifically a `engine_sampler.QuantumEngineSampler`
+            A `cirq.Sampler` instance (specifically a `engine_sampler.ProcessorSampler`
             that will send circuits to the Quantum Computing Service
             when sampled.
 

cirq-google/cirq_google/engine/engine_processor.py

@@ -106,7 +106,7 @@ def get_sampler(self) -> 'cg.engine.ProcessorSampler':
         """Returns a sampler backed by the engine.
 
         Returns:
-            A `cirq.Sampler` instance (specifically a `engine_sampler.QuantumEngineSampler`
+            A `cirq.Sampler` instance (specifically a `engine_sampler.ProcessorSampler`
             that will send circuits to the Quantum Computing Service
             when sampled.1
         """

cirq-google/cirq_google/json_test_data/spec.py

@@ -49,7 +49,6 @@
         'PerQubitDepolarizingWithDampedReadoutNoiseModel',
         'SerializingArg',
         'THETA_ZETA_GAMMA_FLOQUET_PHASED_FSIM_CHARACTERIZATION',
-        'QuantumEngineSampler',
         'ProcessorSampler',
         'ValidatingSampler',
         'CouldNotPlaceError',