[Monitoring] Remove unhelpful Monitoring tests (#30144)

This removes some monitoring tests that have been silenced for a long
time. These tests don't really provide any value for the upgrade suite and
they just create noise due to their occasional timing-related failures.

Author: pickypg

x-pack/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/UpgradeClusterClientYamlTestSuiteIT.java

@@ -42,34 +42,6 @@ public void waitForTemplates() throws Exception {
         XPackRestTestHelper.waitForMlTemplates(client());
     }
 
-    /**
-     * Enables an HTTP exporter for monitoring so that we can test the production-level exporter (not the local exporter).
-     *
-     * The build.gradle file disables data collection, so the expectation is that any monitoring rest tests will use the
-     * "_xpack/monitoring/_bulk" endpoint to lazily setup the templates on-demand and fill in data without worrying about
-     * timing.
-     */
-    @Before
-    public void waitForMonitoring() throws Exception {
-        final String[] nodes = System.getProperty("tests.rest.cluster").split(",");
-        final Map<String, Object> settings = new HashMap<>();
-
-        settings.put("xpack.monitoring.exporters._http.enabled", true);
-        // only select the last node to avoid getting the "old" node in a mixed cluster
-        // if we ever randomize the order that the nodes are restarted (or add more nodes), then we need to verify which node we select
-        settings.put("xpack.monitoring.exporters._http.host", nodes[nodes.length - 1]);
-
-        assertBusy(() -> {
-            final ClientYamlTestResponse response =
-                    getAdminExecutionContext().callApi("cluster.put_settings",
-                                                       emptyMap(),
-                                                       singletonList(singletonMap("transient", settings)),
-                                                       emptyMap());
-
-            assertThat(response.evaluate("acknowledged"), is(true));
-        });
-    }
-
     @AfterClass
     public static void upgradeSecurityIfNecessary() throws Exception {
         if (System.getProperty("tests.rest.suite").equals("old_cluster")) {