Add back-compat indices for 8.9.0

Author: mayya-sharipova

lucene/backward-codecs/src/test/org/apache/lucene/backward_index/TestBackwardsCompatibility.java

@@ -369,7 +369,9 @@ public void testCreateEmptyIndex() throws Exception {
     "8.8.1-cfs",
     "8.8.1-nocfs",
     "8.8.2-cfs",
-    "8.8.2-nocfs"
+    "8.8.2-nocfs",
+    "8.9.0-cfs",
+    "8.9.0-nocfs"
   };
 
   public static String[] getOldNames() {
@@ -395,7 +397,8 @@ public static String[] getOldNames() {
     "sorted.8.7.0",
     "sorted.8.8.0",
     "sorted.8.8.1",
-    "sorted.8.8.2"
+    "sorted.8.8.2",
+    "sorted.8.9.0"
   };
 
   public static String[] getOldSortedNames() {