Mute DedicatedClusterSnapshotRestoreIT#testRestoreShrinkIndex (elastic#38330)

Author: Christoph Büscher

server/src/test/java/org/elasticsearch/snapshots/DedicatedClusterSnapshotRestoreIT.java

@@ -988,6 +988,7 @@ public void testMasterShutdownDuringFailedSnapshot() throws Exception {
      * can be restored when the node the shrunken index was created on is no longer part of
      * the cluster.
      */
+    @AwaitsFix(bugUrl="https://github.com/elastic/elasticsearch/issues/38226")
     public void testRestoreShrinkIndex() throws Exception {
         logger.info("-->  starting a master node and a data node");
         internalCluster().startMasterOnlyNode();