build(deps): bump google-auth-httplib2 from 0.3.1 to 0.4.0

Bumps [google-auth-httplib2](https://github.com/googleapis/google-cloud-python) from 0.3.1 to 0.4.0.
- [Release notes](https://github.com/googleapis/google-cloud-python/releases)
- [Changelog](https://github.com/googleapis/google-cloud-python/blob/main/CHANGELOG.md)
- [Commits](googleapis/google-cloud-python@google-auth-httplib2-v0.3.1...google-auth-httplib2-v0.4.0)

---
updated-dependencies:
- dependency-name: google-auth-httplib2
  dependency-version: 0.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements.txt

@@ -12,7 +12,7 @@ google-ai-generativelanguage==0.6.15
 google-api-core==2.30.3
 google-api-python-client==2.193.0
 google-auth==2.49.2
-google-auth-httplib2==0.3.1
+google-auth-httplib2==0.4.0
 google-genai==1.73.0
 googleapis-common-protos==1.74.0
 grpcio==1.80.0