req-resp: Fix memory leak of pending substreams

Signed-off-by: Alexandru Vasile <[email protected]>

Author: lexnv

src/protocol/request_response/mod.rs

@@ -292,6 +292,9 @@ impl RequestResponseProtocol {
     async fn on_connection_closed(&mut self, peer: PeerId) {
         tracing::debug!(target: LOG_TARGET, ?peer, protocol = %self.protocol, "connection closed");
 
+        // Remove any pending outbound substreams for this peer.
+        self.pending_outbound.retain(|_, context| context.peer != peer);
+
         let Some(context) = self.peers.remove(&peer) else {
             tracing::error!(
                 target: LOG_TARGET,