Fix SLMSnapshotBlockingIntegTests.testSnapshotInProgress (#59218)

Waiting `INIT` here is dead code in newer versions that don't use `INIT`
any longer and leads to nothing being written to the repository in older versions
if the snapshot is cancelled at the `INIT` step which then breaks repo consistency
checks.
Since we have other tests ensuring that snapshot abort works properly we can just remove
the wait for `INIT` here and backport this down to 7.8 to fix tests.

relates #59140

Author: original-brownbear

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

@@ -123,8 +123,8 @@ public void testSnapshotInProgress() throws Exception {
             SnapshotLifecyclePolicyItem.SnapshotInProgress inProgress = item.getSnapshotInProgress();
             assertThat(inProgress.getSnapshotId().getName(), equalTo(snapshotName));
             assertThat(inProgress.getStartTime(), greaterThan(0L));
-            assertThat(inProgress.getState(), anyOf(equalTo(SnapshotsInProgress.State.INIT), equalTo(SnapshotsInProgress.State.STARTED),
-                equalTo(SnapshotsInProgress.State.SUCCESS)));
+            assertThat(inProgress.getState(),
+                    anyOf(equalTo(SnapshotsInProgress.State.STARTED), equalTo(SnapshotsInProgress.State.SUCCESS)));
             assertNull(inProgress.getFailure());
         });