[CI] Add preflight certification job

Summary

Adds preflight certification job to CI, ensuring that tagged releases push the FIPS image to the RedHat portal.

Listing: https://connect.redhat.com/projects/63335544bc888bc1ff145420/overview

Closes gitlab-org/cloud-native/gitlab-operator#862 (closed)

Manual certification

Image from pipeline on master: https://gitlab.com/gitlab-org/cloud-native/charts/gitlab-ingress-nginx/-/jobs/3112643825#L2342

registry.gitlab.com/gitlab-org/cloud-native/charts/gitlab-ingress-nginx/controller:v1.2.1-fips@sha256:c4330aae6a5dcc5c1dbef0f06ec1ede76fb43c3ca2dc8395b19f0284e9258dfc

Certification checklist complete ✅

To do

• Merge !7 (merged)
• Add CI variable with API token
• Submit certification locally
• Merge !9 (merged)