Gitlab: Update to 15.6.1

Package Merge Request

Package Changes

https://repo1.dso.mil/platform-one/big-bang/apps/developer-tools/gitlab/-/blob/6.6.1-bb.0/CHANGELOG.md

Package MR

https://repo1.dso.mil/platform-one/big-bang/apps/developer-tools/gitlab/-/merge_requests/163

For Issue

Closes https://repo1.dso.mil/platform-one/big-bang/apps/developer-tools/gitlab/-/issues/165