release-25.2: colexecjoin: add missing cancellation checking to hash joiner

[yuzefovich]

Backport 1/1 commits from #164879 on behalf of @yuzefovich.

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This commit adds the missing cancellation checking to the hash joiner: namely, previously it was possible to build the hash table (i.e. consume the right input) and then fully build the cross product of the batch from the left input before the cancellation was observed. If the right input was large, say 100k rows, then we'd have materialized about 100M rows before we'd observe the cancellation. This commit adds the cancel checking before every batch emitted by the hash joiner.

Fixes: #163263.

Release note (bug fix): Previously, CockroachDB might not have promptly responded to the statement timeout when performing a hash join with ON filter that is mostly false. This is now fixed.

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Release justification: stability fix - without it, a query might not be cancelable (without CRDB process restart) for a while.

[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.

All backports must be reviewed by the TL and EM for the owning area.

[blathers-crl]

It looks like your PR touches production code but doesn't add or edit any test code. Did you consider adding tests to your PR?

_{🦉 Hoot! I am a Blathers, a bot for CockroachDB. My owner is dev-inf.}

[cockroach-teamcity]

This change is 

[blathers-crl]

✅ PR #164889 is compliant with backport policy

Confidence: high
Critical bug criteria met: [Stability or security issues]
Backward compatible: true
Explanation: The pull request meets the CockroachDB backport policy. It contains a 'Release justification: stability fix - without it, a query might not be cancelable (without CRDB process restart) for a while.' in the body, which exempts it from the standard backport policy requirements. The change addresses a stability issue, further justified by the nature of the bug fix described in the PR. The fix improves the responsiveness of the database to cancellation requests during hash joins, thereby enhancing system stability and behavior under cancellation conditions, such as reaching a statement timeout.

❌ ENGREQ Check Failed: Please check one of the backport category checkboxes.

_{🦉 Hoot! I am a Blathers, a bot for CockroachDB. My owner is dev-inf.}

[mw5h]

@mw5h made 1 comment.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on yuzefovich).