Remove unused method

Author: pzygielo

nucleus/common/amx-core/src/main/java/org/glassfish/admin/amx/impl/mbean/MBeanImplBase.java

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2025 Contributors to the Eclipse Foundation. All rights reserved.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0, which is available at
@@ -438,19 +439,6 @@ protected void debug(final Object... args) {
             debug(StringUtil.toString("", args));
         }
     }
-
-    protected boolean sleepMillis(final long millis) {
-        boolean interrupted = false;
-
-        try {
-            Thread.sleep(millis);
-        } catch (InterruptedException e) {
-            Thread.interrupted();
-            interrupted = true;
-        }
-
-        return interrupted;
-    }
 }