fix(anti-abuse): cancel in-flight CI on a blacklist close, not just contributor_cap

[JSONbored]

The contributor-cap close disposition (#2462) cancels in-flight/queued GitHub Actions runs for the closed PR's head SHA when contributorCapCancelCi is enabled. The contributor-blacklist close disposition (#1425) does not — a banned login's CI keeps running to completion even though the PR is closed deterministically ahead of any review. Extend the same cancellation to closeKind: "blacklist", unconditionally (no separate config toggle — there's no legitimate reason to let a permanently-banned login's CI keep burning minutes after the close).

[linear-code]

JSO-4540