Revert "Merge branch 'run-gems-specs-in-maintenance-pipelines'"

What does this MR do and why?

Revert "Merge branch 'run-gems-specs-in-maintenance-pipelines' into 'master'"

This reverts merge request !125859 (merged) since gems pipelines cannot be created due to:

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.