The feature flag has been enabled by default on GitLab.com for several
days now with no issues. We can now drop the flag and changes relating
to making it scoped to the project
(https://gitlab.com/gitlab-org/gitlab/-/merge_requests/98010).

This will make it easier to support using the CDN for Web UI downloads
(https://gitlab.com/gitlab-org/gitlab/-/issues/378473).

Relates to https://gitlab.com/gitlab-org/gitlab/-/issues/373860

Changelog: changed