Complete Jetty frame callback when opcode is not PONG

The onWebSocketFrame method should complete callback.
For more details, see jetty/jetty.project#11088.

Closes gh-31869

spring-websocket/src/main/java/org/springframework/web/socket/adapter/jetty/JettyWebSocketHandlerAdapter.java

@@ -115,6 +115,9 @@ public void onWebSocketFrame(Frame frame, Callback callback) {
 				ExceptionWebSocketHandlerDecorator.tryCloseWithError(this.wsSession, ex, logger);
 			}
 		}
+		else {
+			callback.succeed();
+		}
 	}
 
 	private static ByteBuffer copyByteBuffer(ByteBuffer src) {