Merge branch 'update-gitlab-tag-6.1.2-bb.0' into 'master'

Update Gitlab to 15.1.2

Closes platform-one/big-bang/apps/developer-tools/gitlab#145, platform-one/big-bang/apps/developer-tools/gitlab#144, and platform-one/big-bang/apps/developer-tools/gitlab#142

See merge request platform-one/big-bang/bigbang!1881