Make disabling TerraformNotification banner possible

A GitLab Premium customer with 13k seats is reporting internally that the "Using Terraform? Try the GitLab Managed Terraform State" banner is

… causing a lot of confusion for our users and we need to disable it. Is there a feature flag or method available to disable the banner?

This was introduced & refined via:

  1. !65870 (merged)
  2. !68135 (merged)
  3. !68064 (merged)

Having skimmed the code, I believe there is no built-in method to disable the banner. Can we add one, or limit the display to the GitLab.com instance?

Edited by Katrin Leinweber