Bump google-auth from 2.16.0 to 2.16.1 in /tests (#3568)

Bumps [google-auth](https://github.com/googleapis/google-auth-library-python) from 2.16.0 to 2.16.1.
- [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](googleapis/google-auth-library-python@v2.16.0...v2.16.1)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

tests/requirements.txt

@@ -129,9 +129,9 @@ flaky==3.7.0 \
 forcediphttpsadapter==1.0.2 \
     --hash=sha256:f7582b34aaa6ab6b17f69ab1abbfe67097b952ed0682b758b5e01e18fe24433e
     # via -r requirements.txt
-google-auth==2.16.0 \
-    --hash=sha256:5045648c821fb72384cdc0e82cc326df195f113a33049d9b62b74589243d2acc \
-    --hash=sha256:ed7057a101af1146f0554a769930ac9de506aeca4fd5af6543ebe791851a9fbd
+google-auth==2.16.1 \
+    --hash=sha256:5fd170986bce6bfd7bb5c845c4b8362edb1e0cba901e062196e83f8bb5d5d32c \
+    --hash=sha256:75d76ea857df65938e1f71dcbcd7d0cd48e3f80b34b8870ba229c9292081f7ef
     # via
     #   -r requirements.txt
     #   kubernetes