[CI] Functional test cleanup jobs run even if functional tests never ran

Summary

The functional tests cleanup template specifies when: always. This means that any failure in the pipeline will trigger these cleanup jobs.

However, these cleanup jobs are only relevant if the functional tests jobs actually ran and deployed to the CI clusters.

To avoid this, we can:

• Allow failure for these jobs (easiest solution, but not the cleanest)
• Ensure that cleanup jobs are only run if functional test jobs deployed to CI clusters (perhaps GitLab CI environments will help here)