[Test] Fix FullClusterRestartIT.testShrink() with copy_settings param (#34853)

The pull request #34338 added strict deprecation mode to the REST tests
and adds the copy_settings param when testing the shrink of an index.

This parameter has been added in 6.4.0 and will be removed in 8.0, so
the test now needs to take care of the old cluster version when adding
the copy_settings param.

Author: tlrx

qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/FullClusterRestartIT.java

@@ -325,7 +325,6 @@ public void testClusterState() throws Exception {
 
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/pull/34853")
     public void testShrink() throws IOException {
         String shrunkenIndex = index + "_shrunk";
         int numDocs;
@@ -364,7 +363,9 @@ public void testShrink() throws IOException {
             client().performRequest(updateSettingsRequest);
 
             Request shrinkIndexRequest = new Request("PUT", "/" + index + "/_shrink/" + shrunkenIndex);
-            shrinkIndexRequest.addParameter("copy_settings", "true");
+            if (getOldClusterVersion().onOrAfter(Version.V_6_4_0)) {
+                shrinkIndexRequest.addParameter("copy_settings", "true");
+            }
             shrinkIndexRequest.setJsonEntity("{\"settings\": {\"index.number_of_shards\": 1}}");
             client().performRequest(shrinkIndexRequest);