curl: 11: `CURLOPT_FORBID_REUSE` silently lost on multiplexed HTTP/2 connection when the forbidding transfer finishes first

Summary When HTTP/2 transfers share a multiplexed connection, CURLOPTFORBIDREUSE set by a transfer that completes before the other active streams is silently discarded. The connection survives into the idle pool and can be reused by a subsequent transfer. This breaks the mitigation documented in...