fix: include amended user agent in read client

[tswast]

Towards internal issue b/526614511 🦕

[gemini-code-assist]

Code Review

This pull request reorganizes imports across several files and updates the _ensure_bqstorage_client method in client.py to append pandas-gbq version information to the client_info user agent when initializing the BigQueryReadClient. It also adds comprehensive unit tests to verify this behavior under different scenarios. The review feedback suggests adding a # type: ignore[assignment] comment to the fallback assignment pandas_gbq = None to prevent potential mypy type-checking errors.

[parthea]

From https://github.com/googleapis/google-cloud-python/actions/runs/28405657720/job/84167435143?pr=17592,

E           AttributeError: 'ClientInfo' object has no attribute 'protobuf_runtime_version'

protobuf_runtime_version requires google-api-core 2.25 or newer: https://github.com/googleapis/python-api-core/releases/tag/v2.25.0

>>> import google.api_core.gapic_v1.client_info as client_info
>>> hasattr(client_info.ClientInfo(), 'protobuf_runtime_version')
True

See similar code in google-cloud-language:

google-cloud-python/packages/google-cloud-language/google/cloud/language_v1/services/language_service/client.py

Lines 1513 to 1518 in 0dfdf44

	DEFAULT_CLIENT_INFO = gapic_v1.client_info.ClientInfo(
	gapic_version=package_version.__version__
	)
	if hasattr(DEFAULT_CLIENT_INFO, "protobuf_runtime_version"): # pragma: NO COVER
	DEFAULT_CLIENT_INFO.protobuf_runtime_version = google.protobuf.__version__

Alternatively, we could bump the minimum version of google-api-core since we currently have 2.24.2. Bumping to 2.25 seems reasonable

google-cloud-python/packages/gapic-generator/gapic/templates/setup.py.j2

Line 39 in 0dfdf44

"google-api-core[grpc] >= 2.24.2, <3.0.0",

[parthea]

See WIP PR #17599 to bump google-api-core for generated libraries. You can also bump google-api-core in this PR for google-cloud-bigquery since it's not automatically generated .

[tswast]

Thanks for investigating @parthea ! Yes, I'll bump the minimum here too.

[parthea]

Switching to draft until presubmits are green