Revert "Merge branch 'sc1-optimise-concurrency-tracking' into 'master'"

Purpose of revert

Revert "Merge branch 'sc1-optimise-concurrency-tracking' into 'master'"

This reverts merge request !167027 (merged)

There seems to have been some problem with our new concurrency limit checks (even when the feature flag was off) per this discussion #490936 (comment 2156584549) .

Incident: gitlab-com/gl-infra/production#18702 (closed)

Checklist

• Create an issue to reinstate the merge request and assign it to the author of the reverted merge request.
• If the revert is to resolve a broken 'master' incident, please read through the Responsibilities of the Broken master resolution DRI.
• If the revert involves a database migration, please read through Deleting existing migrations.
• Add the appropriate labels before the MR is created. We can skip CI/CD jobs only if the labels are added before the CI/CD pipeline is created.

Milestone info

• I am reverting something in the current milestone. No changelog is needed, and I've added a ~"regression:*" label.
• I am reverting something in a different milestone. A changelog is needed, and I've removed the ~"regression:*" label.

Related issues and merge requests