[CI] Use vcluster for smoke testing on Kubernetes

What does this MR do?

This adds new pipelines to test deployment targeting multiple k8s versions. These k8s clusters are lightweight k3s clusters provisioned using vcluster. None of the other existing pipelines have been changed.

The overall strategy includes:

• use the GKE 1.27 cluster as the host cluster (this can be changed)
• create a vcluster in a separate namespace in the host cluster
• use part of the existing test.sh script and the build and create templates to install the operator
• a cleanup job can delete all the vcluster namespace using a label selector
• the operator deployment requires cert-manager CRDs so cert-manager is installed in each vcluster

By only deploying the operator with helm and checking the k8s probes are green (and not testing actual gitlab instances) we greatly simplify these tests and can avoid issues with ingress and egress with vclusters. It is left to future to work to convert the full test suite to make use of vclusters.

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• Merge Request Title and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com
• When ready for review, MR is labeled "~workflow::ready for review" per the Distribution MR workflow

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Tests added
• Integration tests added to GitLab QA
• Equivalent MR/issue for omnibus-gitlab opened
• Validate potential values for new configuration settings. Formats such as integer 10, duration 10s, URI scheme://user:passwd@host:port may require quotation or other special handling when rendered in a template and written to a configuration file.

Related issues

Part of #1419 (closed)