Regenerate GAPIC client to include QuantumEngineService.ListQuantumProcessorConfigs

[hoisinberg]

The changes in each commit include:

1. (987ea2b) Contains only code generated by GAPIC.
2. (965d0a4) Remove files named gapic_version.py and all references to their contents. Rename packages starting with google.cloud.quantum_v1alpha1 to cirq_google.cloud.quantum_v1alpha1.
3. (4a6bb73) Formatted with ./check/format-incremental --apply.
4. (66d48ba) Applied linter fixes with ruff check --fix.
5. (bbe3f08) Reran ./check/format-incremental --apply.

[codecov]

Codecov Report

❌ Patch coverage is 61.99095% with 84 lines in your changes missing coverage. Please review.
✅ Project coverage is 97.40%. Comparing base (9672295) to head (bbe3f08).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
...v1alpha1/services/quantum_engine_service/pagers.py	34.00%	33 Missing ⚠️
...a1/services/quantum_engine_service/async_client.py	32.00%	17 Missing ⚠️
...v1alpha1/services/quantum_engine_service/client.py	50.00%	17 Missing ⚠️
...ces/quantum_engine_service/transports/rest_base.py	79.59%	10 Missing ⚠️
...services/quantum_engine_service/transports/grpc.py	75.00%	3 Missing ⚠️
.../quantum_engine_service/transports/grpc_asyncio.py	72.72%	3 Missing ⚠️
...cirq_google/cloud/quantum_v1alpha1/types/engine.py	92.30%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7631      +/-   ##
==========================================
- Coverage   97.50%   97.40%   -0.10%     
==========================================
  Files        1103     1103              
  Lines       99709    99898     +189     
==========================================
+ Hits        97222    97307      +85     
- Misses       2487     2591     +104     

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