Remove `xray_scan` job in `.gitlab-ci.yml`

Context

As part of the %18.0 major version changes, we are removing support for Repository X-Ray jobs in the CI Pipeline. This has now been deprecated and replaced with a Repository X-Ray background worker that runs whenever a new commit is pushed to a repository (see documentation).

We still have GitLab projects that have the Repository X-Ray job configured in .gitlab-ci.yml. We need to remove these jobs before %18.0.

References

Epic: X-Ray should not run as a CI job (&14100)

Proposal

Remove the Repository X-ray CI jobs in the following projects:

GitLab Monolith

Repositories

• gitlab-org/gitlab
• gitlab-org/security/gitlab
• gitlab-org/security/gitlab-foss
• gitlab-community/gitlab
• gitlab-org/frontend/gitlab-ui-integrations

Change needed

The list above is not complete, but with the GitLab monolith, we only need to update the gitlab-org/gitlab repository.

Remove the xray_scan job in .gitlab/ci/reports.gitlab-ci.yml, see https://gitlab.com/gitlab-org/gitlab/-/blob/master/.gitlab/ci/reports.gitlab-ci.yml#L112-L130