Raise iosqeAsyncThreshold (#8252)

plaintext benchmark can cause Netty io_uring to use ASYNC SQEs that are not nicely handled at OS level (creating TONS of kernel threads) ie 16384 connections / 28 event loops = 582 connections per event loop which can use SYNC SEQs, which exceed the 25 default ones.
  
This PR fix this behaviour and force SYNC SQEs: see https://github.com/netty/netty-incubator-transport-io_uring/issues/152#issuecomment-1077363041 for more info

frameworks/Java/netty/netty.dockerfile

@@ -10,4 +10,4 @@ COPY --from=maven /netty/target/netty-example-0.1-jar-with-dependencies.jar app.
 
 EXPOSE 8080
 
-CMD ["java", "-server", "-XX:+UseNUMA", "-XX:+UseParallelGC", "-XX:+AggressiveOpts", "-Dio.netty.buffer.checkBounds=false", "-Dio.netty.buffer.checkAccessible=false", "-jar", "app.jar"]
+CMD ["java", "-server", "-XX:+UseNUMA", "-XX:+UseParallelGC", "-XX:+AggressiveOpts", "-Dio.netty.buffer.checkBounds=false", "-Dio.netty.buffer.checkAccessible=false", "-Dio.netty.iouring.iosqeAsyncThreshold=32000", "-jar", "app.jar"]