Revert "Add getter to IndexNameExpressionResolve (elastic#96150)" (elastic#96255)

This reverts commit 3c5ab9c.

Author: pxsalehi

server/src/main/java/org/elasticsearch/cluster/metadata/IndexNameExpressionResolver.java

@@ -1699,8 +1699,4 @@ public IndicesOptions getOptions() {
     private static boolean isWildcard(String expression) {
         return Regex.isSimpleMatchPattern(expression);
     }
-
-    public SystemIndices getSystemIndices() {
-        return systemIndices;
-    }
 }