Under the hood
Domain blocklist check can now be cancelled mid-flight instead of just timing out
What
The internal check that looks up whether a domain is blocklisted now accepts a cancellation signal. If the check is aborted, it re-raises the abort instead of silently treating it as a failed check, and a cleanup step now always runs afterward to clear its timer.
Why
This distinguishes a genuinely cancelled lookup from a failed one, and prevents leftover timers from lingering after the check finishes or is cancelled.