Upgrade Gitlab helm chart for review-apps to the most current version

Context

We are a few versions behind for the review-apps Gitlab helm chart. We should update this dependency regularly to reduce technical debt down the line.

Goal

• Upgrade one minor version at a time
  • from 6.9.x to 6.10.x
  • from 6.10.x to 6.11.x
  • from 6.11.x to 7.0.x