Merge branch 'remove-ff-ci-include-rules-when-never' into 'master'

Remove feature flag `ci_support_include_rules_when_never`

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/124786



Merged-by: Furkan Ayhan <furkanayhn@gmail.com>
Approved-by: Marcel Amirault <mamirault@gitlab.com>
Approved-by: Jerry Seto <jseto@gitlab.com>
Approved-by: Furkan Ayhan <furkanayhn@gmail.com>
Co-authored-by: lma-git <lma@gitlab.com>