Add index on ci_runners.contacted_at

What does this MR do?

It adds an index on ci_runners.contacted_at.

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #31229 (closed)

added 1 commit

• 1b44565e - Add index on ci_runners.contacted_at

Compare with previous version

unmarked as a Work In Progress

marked the checklist item Changelog entry added, if necessary as completed

marked the checklist item Branch has no merge conflicts with master (if it does - rebase it please) as completed

marked the checklist item Squashed related commits together as completed

@yorickpeterse, could you review the code, please?

assigned to @yorickpeterse

approved this merge request

changed milestone to %9.1

enabled an automatic merge when the pipeline for 1b44565e succeeds

@blackst0ne Please rebase and reassign to an endboss, thanks! (you'll probably want to wait for !10874 (closed) to be merged, though).

assigned to @blackst0ne

I'll rebase this MR when !10874 (closed) is merged.

added 241 commits

• 1b44565e...8fbda3bf - 240 commits from branch gitlab-org:master
• 4c6e2914 - Add index on ci_runners.contacted_at

Compare with previous version

I've rebased the code.

assigned to @yorickpeterse

@blackst0ne There are some failing specs again :<, could you look into these?

added 33 commits

• 4c6e2914...43fb9279 - 32 commits from branch gitlab-org:master
• 25e9f229 - Add index on ci_runners.contacted_at

Compare with previous version

Rebased again.
All tests are green.

I wonder how we could ditch contacted_at at all.

added 1 commit

• 239c2d14 - Add index on ci_runners.contacted_at

Compare with previous version

added 73 commits

• 239c2d14...479d21d5 - 72 commits from branch gitlab-org:master
• 720ee139 - Add index on ci_runners.contacted_at

Compare with previous version

There were merge conflicts.
Rebased again.

added 1 commit

• 4aa984fa - Add index on ci_runners.contacted_at

Compare with previous version

approved this merge request

merged

mentioned in commit f2d637f7

mentioned in issue #31550 (closed)

mentioned in commit fc9f6c6d

Picked into 9-1-stable, will go into 9.1.2.