Add CI jobs to test against the the Kubernetes 1.25 cluster

Summary

First needs the cluster to be created in gitlab-org/charts/gitlab#4102 (closed)

Then we need to add the Cluster to our CI, and add the CI jobs to run against it.

It's likely that initially in the MR, that CI will fail with some incompatabilities, these should be logged as issues and added to the Support deploying GitLab on Kubernetes 1.25 (gitlab-org&7599 - closed) epic.

See gitlab-org/charts/gitlab#3018 (closed) for the last time we added a new cluster.