Don't unwrap on bad zstd data (#27891)

Closes #ISSUE

Release Notes:

- N/A

crates/rpc/src/proto.rs

@@ -88,7 +88,7 @@ where
             let received_at = Instant::now();
             match bytes? {
                 WebSocketMessage::Binary(bytes) => {
-                    zstd::stream::copy_decode(bytes.as_slice(), &mut self.encoding_buffer).unwrap();
+                    zstd::stream::copy_decode(bytes.as_slice(), &mut self.encoding_buffer)?;
                     let envelope = Envelope::decode(self.encoding_buffer.as_slice())
                         .map_err(io::Error::from)?;