Bump google-auth from 2.4.1 to 2.6.0 in /requirements (#18731)
Bump google-auth from 2.4.1 to 2.6.0 in /requirements (#18731)

Bumps [google-auth](https://github.com/googleapis/google-auth-library-python) from 2.4.1 to 2.6.0.
- [Release notes](https://github.com/googleapis/google-auth-library-python/releases)
- [Changelog](https://github.com/googleapis/google-auth-library-python/blob/main/CHANGELOG.md)
- [Commits](https://github.com/googleapis/google-auth-library-python/compare/v2.4.1...v2.6.0)

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

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>

Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
mozilla/addons-server,mozilla/olympia,mozilla/addons-server,mozilla/olympia,diox/olympia,wagnerand/addons-server,wagnerand/addons-server,diox/olympia,mozilla/olympia,wagnerand/addons-server,mozilla/olympia,mozilla/addons-server,wagnerand/addons-server,diox/olympia,diox/olympia,mozilla/addons-server