Merge branch '40230-groups-gitlab-org-labels-json-redirects-to-groups-gitlab-org-labels-json' into 'master'

Resolve "/groups/gitlab-org/labels.json redirects to /groups/gitlab-org/-/labels/.json"

Closes #40230

See merge request gitlab-org/gitlab-ce!15427

(cherry picked from commit 7142af49)

9f921b73 Don't add a trailing slash in group redirects