Expand cookbook test suites to include all currently in-use ubuntu versions
We've had a few cases recently during attempts to upgrade to 18.04 or 20.04 where the upgrade failed due to missing packages or other changes in the base image.
Examples:
We can increase our chances of catching such issues earlier by including those versions in all cookbook kitchen tests.
Note: We may need to also perform the move of cookbook tests to GCP, see https://gitlab.com/gitlab-com/gl-infra/infrastructure/-/issues/8854.