v0.95.0

• Use Protocol::HTTP::RefusedError for safe retry of requests not processed by the server, including non-idempotent methods like PUT.
  • Remove Async::HTTP::Protocol::RequestFailed in favour of Protocol::HTTP::RefusedError.
  • HTTP/1: Delegate request write failure handling to protocol-http1.
  • HTTP/2: Handle GOAWAY and REFUSED_STREAM via protocol-http2, enabling automatic retry of unprocessed requests.