www/gitlab-ce: use sidekiq from ports

The vendored sidekiq version does pollute the build environment, as
it does not respect the STAGEDIR.
As the vendored gem is maybe only a temporary solution:
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/142986

till these changes are fixed upstream, I will switch back to
the sidekiq 7.1.6 version provided via ports.

(cherry picked from commit 5a638f64132ce3edc3991a2672ac524d95b06030)