Ubuntu version changes

[gcagle3]

Description

Removes EOL Ubuntu 16.04 and 18.04 tests. Adds tests for Ubuntu 22.04.

TODOs

Please ensure all of these TODOs are completed before asking for a review.

• [x] Ensure the branch is named correctly with the issue number. e.g: feature/new-vpc-endpoints-955 or bug/missing-count-param-434.
• [x] Update the docs.
• [x] Keep the changes backward compatible where possible.
• [x] Run the pre-commit checks successfully.
• [ ] Run the relevant tests successfully.
• [x] Ensure any 3rd party code adheres with our license policy or delete this line if its not applicable.

Related Issues

Fixes #65