Perform a WME Gitlab ugrade.
There are several manual steps that need to be accomplished to finisht the upgrade.
**Acceptance criteria**
# Gitlab is running on the latest 16.x vetrion available for Community Edition
# Gitlab Upgrade Documentation is updated with all the latest details.
**ToDo**
- [ ] explore upgrade path
- [ ] decide the timeframe
- [ ] prepare backups, in addition to the existing automated backups
- [ ] upgrade the Gitlab
- [ ] update the Giltab Upgrade Documentation
===== Test Strategy =====
**Checklist for testing**
- [ ] Engineers are able to login to Gitlab using 2FA
- [ ] Engineers are able to push and pull the code
- [] Pipelines are fully operational
- [ ] serverless runners setup works as expected
===== Things to consider: =====
* Should be executed during the least loaded hours, not to block the development flows.