Merge branch '420372-feature-flag-cleanup-standalone_finding_modal-frontend' into 'master'

Resolve "[Feature flag] Cleanup standalone_finding_modal"

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/131481



Merged-by: Shinya Maeda <shinya@gitlab.com>
Approved-by: Shinya Maeda <shinya@gitlab.com>
Approved-by: Savas Vedova <svedova@gitlab.com>
Approved-by: mo khan <mo@mokhan.ca>
Approved-by: Samantha Ming <sming@gitlab.com>
Co-authored-by: Dave Pisek <dpisek@gitlab.com>