chore: Update IOUtils.java (googleapis#1661)

Adding `@Deprecated` to match the `@deprecated` annotation.

Author: sduskis

google-http-client/src/main/java/com/google/api/client/util/IOUtils.java

@@ -179,6 +179,7 @@ public static <S extends Serializable> S deserialize(InputStream inputStream) th
    * @since 1.16
    * @deprecated use java.nio.file.Path#isSymbolicLink
    */
+  @Deprecated
   public static boolean isSymbolicLink(File file) throws IOException {
     // first try using Java 7
     try {