Backports more blocking fixes

spring-cloud-gateway-core/src/test/java/reactor/blockhound/integration/CustomBlockHoundIntegration.java

@@ -25,6 +25,12 @@ public class CustomBlockHoundIntegration implements BlockHoundIntegration {
 
 	@Override
 	public void applyTo(BlockHound.Builder builder) {
+		/*builder.blockingMethodCallback(it -> {
+			Error error = new Error(it.toString());
+			error.printStackTrace();
+			throw error;
+		});*/
+
 		// Uses
 		// ch.qos.logback.classic.spi.PackagingDataCalculator#getImplementationVersion
 		builder.allowBlockingCallsInside(
@@ -62,6 +68,8 @@ public class CustomBlockHoundIntegration implements BlockHoundIntegration {
 		// Uses Unsafe#park
 		builder.allowBlockingCallsInside("io.netty.util.concurrent.GlobalEventExecutor",
 				"execute");
+		builder.allowBlockingCallsInside(
+				"io.netty.util.concurrent.SingleThreadEventExecutor$6", "run");
 
 		// SECURITY RELATED