Disable EPOLL in VirtualMultithreadIoEventLoopGroupTest due to known issue

Author: franz1981

core/src/test/java/io/netty/loom/VirtualMultithreadIoEventLoopGroupTest.java

@@ -70,7 +70,8 @@ boolean isLocal() {
 		boolean isAvailable() {
 			return switch (this) {
 				case NIO -> true;
-				case EPOLL -> Epoll.isAvailable();
+                // TODO disable EPOLL due to https://github.com/netty/netty/issues/15922
+				case EPOLL -> false;
 				case IO_URING -> IoUring.isAvailable();
 				case LOCAL -> true;
 				default -> false;