Fix SLMSnapshotBlockingIntegTests (elastic#47841)

One of the tests in this suit stops a master node,
plus we're doing other node starts in this suit.
=> the internal test cluster should be TEST and not `SUITE`
scoped to avoid random failures like the one in elastic#47834

Closes elastic#47834

x-pack/plugin/ilm/src/test/java/org/elasticsearch/xpack/slm/SLMSnapshotBlockingIntegTests.java

@@ -60,6 +60,7 @@
  */
 @TestLogging(value = "org.elasticsearch.snapshots.mockstore:DEBUG",
              reason = "https://github.com/elastic/elasticsearch/issues/46508")
+@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST)
 public class SLMSnapshotBlockingIntegTests extends ESIntegTestCase {
 
     private static final String REPO = "repo-id";
@@ -167,7 +168,6 @@ public void testSnapshotInProgress() throws Exception {
         }
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/47834")
     public void testRetentionWhileSnapshotInProgress() throws Exception {
         final String indexName = "test";
         final String policyId = "slm-policy";