Fix CloseFollowerIndexIT (#105351) (#105355)

There's no particular reason that the closed follower index should be
`RED` - if it is closed at a point where there are no indexing requests
in flight then its shards can be assigned and it could even reach
`GREEN` health.

This commit fixes the problem by removing the bogus assertion.

Closes #104865

Author: DaveCTurner

x-pack/plugin/ccr/src/internalClusterTest/java/org/elasticsearch/xpack/ccr/CloseFollowerIndexIT.java

@@ -12,7 +12,6 @@
 import org.elasticsearch.action.support.ActiveShardCount;
 import org.elasticsearch.action.support.master.AcknowledgedResponse;
 import org.elasticsearch.cluster.ClusterState;
-import org.elasticsearch.cluster.health.ClusterHealthStatus;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.metadata.MetadataIndexStateService;
 import org.elasticsearch.common.unit.ByteSizeValue;
@@ -110,7 +109,6 @@ public void testCloseAndReopenFollowerIndex() throws Exception {
         ClusterState clusterState = followerClient().admin().cluster().prepareState().get().getState();
         assertThat(clusterState.metadata().index("index2").getState(), is(IndexMetadata.State.CLOSE));
         assertThat(clusterState.getBlocks().hasIndexBlock("index2", MetadataIndexStateService.INDEX_CLOSED_BLOCK), is(true));
-        assertThat(followerClient().admin().cluster().prepareHealth("index2").get().getStatus(), equalTo(ClusterHealthStatus.RED));
 
         isRunning.set(false);
         for (Thread thread : threads) {