release-24.3: roachtest: add async association tests to activerecord ignore list

[spilchen]

Backport 1/1 commits from #168318 on behalf of @spilchen.

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The AsyncBelongsToAssociationsTest, AsyncHasManyAssociationsTest, and AsyncHasOneAssociationsTest tests all use a wait_for_async_query helper with a 5-second timeout that flakes on CI when CockroachDB query execution exceeds the deadline. These are the same class of flake as the five LoadAsyncTest entries already on the ignore list (added in d5431d9 for #162147), but the association test variants were missed at that time.

Closes: #164804
Epic: none

Release note: None

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Release justification: test only fix

[trunk-io]

😎 Merged directly without going through the merge queue, as the queue was empty and the PR was up to date with the target branch - details.

[blathers-crl]

Thanks for opening a backport.

Before merging, please confirm that it falls into one of the following categories (select one):

• Non-production code changes OR fixes for serious issues. Non-production includes test-only changes, build system changes, etc. Serious issues are defined in the policy as correctness, stability, or security issues, data corruption/loss, significant performance regressions, breaking working and widely used functionality, or an inability to detect and debug production issues.
• Other approved changes. These changes must be gated behind a disabled-by-default feature flag unless there is a strong justification not to. Reference the approved ENGREQ ticket in the PR body (e.g., "Fixes ENGREQ-123").

Add a brief release justification to the PR description explaining your selection.

Also, confirm that the change does not break backward compatibility and complies with all aspects of the backport policy.

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[cockroach-teamcity]

This change is 

[spilchen]

/trunk merge