DRIVERS-2878 OIDC Atlas Testing Updates

Please complete the following before merging:

[x] Update changelog.
[ ] Make sure there are generated JSON files from the YAML test files.
[x] Test changes in at least one language driver. https://github.com/mongodb/mongo-python-driver/pull/1567
[ ] Test these changes against all server versions and topologies (including standalone, replica set, sharded clusters, and serverless).

mongodb / specifications