Security fix in ConcurrencyLimitedModel changes limiter sharing in v2.53.0.

The official source reports this update: v2.53.0 (2026-10-01). 🛡️ Security This release fixes one security issue in ConcurrencyLimitedModel . See the advisory for full details and affected versions. GHSA-6fqq-452j-qhrp (high): a streamed request through ConcurrencyLimitedModel or limit_model_concurrency could keep its concurrency slot when the slot was released on a different task than the one that acquired it: after an early exit (the consumer stopped iterating, raised, or was cancelled), and also after fully consuming stream_text() with its default debouncing. Repeated streams could then block every request sharing the limiter.