…hon-docs-samples#1903)

* updated kms samples to use new gapic client library

Updates docstrings in `google/auth/transport/urllib3.py` to reference
`urllib3.PoolManager` instead of the removed/private
`urllib3.request.RequestMethods`, ensuring compatibility with `urllib3`
v2 documentation standards.

NOTE: This PR supercedes an [older PR
#1290](googleapis/google-auth-library-python#1290),
because some of the content or suggested changes in the older PR are
overtaken by events and/or been incorporated via [other recent
PRs](googleapis/google-auth-library-python#1389).

---
*PR created automatically by Jules for task
[17649723998293325458](https://jules.google.com/task/17649723998293325458)
started by @chalmerlowe*

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>
Co-authored-by: Chalmer Lowe <chalmerlowe@google.com>

PR created by the Librarian CLI to initialize a release. Merging this PR
will auto trigger a release.

Librarian Version: v1.0.1
Language Image:
us-central1-docker.pkg.dev/cloud-sdk-librarian-prod/images-prod/python-librarian-generator@sha256:b8058df4c45e9a6e07f6b4d65b458d0d059241dd34c814f151c8bf6b89211209
<details><summary>google-auth: 2.46.0</summary>

##
[2.46.0](googleapis/google-auth-library-python@v2.45.0...v2.46.0)
(2026-01-05)

### Features

* Recognize workload certificate config in
has_default_client_cert_source for mTLS for Agentic Identities (#1907)
([0b9107d5](googleapis/google-auth-library-python@0b9107d5))

### Bug Fixes

* Fix test coverage for mtls_helper (#1886)
([02e71631](googleapis/google-auth-library-python@02e71631))

* use .read() instead of .content.read() in aiohttp transport (#1899)
([12f4470f](googleapis/google-auth-library-python@12f4470f))

* add types to default and verify_token and Request __init__ based on
comments in the source code. (#1588)
([59a5f588](googleapis/google-auth-library-python@59a5f588))

* fix the document of secure_authorized_session (#1536)
([5d001470](googleapis/google-auth-library-python@5d001470))

* raise RefreshError for missing token in impersonated credentials
(#1897)
([94d04e09](googleapis/google-auth-library-python@94d04e09))

* remove setup.cfg configuration for creating universal wheels (#1693)
([c767531c](googleapis/google-auth-library-python@c767531c))

### Documentation

* update urllib3 docstrings for v2 compatibility (#1903)
([3f1aeea2](googleapis/google-auth-library-python@3f1aeea2))

</details>