PromQL: Disable GenerativeFork for PromQL

Author: costin

x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/generative/GenerativeForkRestTest.java

@@ -60,6 +60,11 @@ protected void shouldSkipTest(String testName) throws IOException {
             testCase.requiredCapabilities.contains(SUBQUERY_IN_FROM_COMMAND.capabilityName())
         );
 
+        assumeFalse(
+            "Tests using PROMQL are not supported for now",
+            testCase.requiredCapabilities.contains(PROMQL_V0.capabilityName())
+        );
+
         assumeTrue("Cluster needs to support FORK", hasCapabilities(adminClient(), List.of(FORK_V9.capabilityName())));
     }
 }