Bump pymongo from 4.1.1 to 4.2.0 (#1091)

Bumps [pymongo](https://github.com/mongodb/mongo-python-driver) from 4.1.1 to 4.2.0.
- [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@4.1.1...4.2.0)

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

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

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

Author: dependabot[bot]

requirements_dev_optional.txt

@@ -10,7 +10,7 @@ azure-storage-blob==12.13.0 # pyup: ignore
 redis==4.3.4
 types-redis
 types-setuptools
-pymongo==4.1.1
+pymongo==4.2.0
 # optional test requirements
 tox==3.25.1
 coverage