Bump pymongo from 4.5.0 to 4.6.1 in /maintenance

Bumps [pymongo](https://github.com/mongodb/mongo-python-driver) from 4.5.0 to 4.6.1.
- [Release notes](https://github.com/mongodb/mongo-python-driver/releases)
- [Changelog](https://github.com/mongodb/mongo-python-driver/blob/master/doc/changelog.rst)
- [Commits](mongodb/mongo-python-driver@4.5.0...4.6.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Diff for: maintenance/requirements.txt

@@ -38,7 +38,7 @@ pyasn1-modules==0.3.0
     # via google-auth
 pycparser==2.21
     # via cffi
-pymongo==4.5.0
+pymongo==4.6.1
     # via -r requirements.in
 pyopenssl==23.3.0
     # via -r requirements.in