Added license header.

contrib/format-xml/src/test/resources/xml/no_nest.xml

@@ -1,3 +1,22 @@
+<!--
+
+    Licensed to the Apache Software Foundation (ASF) under one
+    or more contributor license agreements.  See the NOTICE file
+    distributed with this work for additional information
+    regarding copyright ownership.  The ASF licenses this file
+    to you under the Apache License, Version 2.0 (the
+    "License"); you may not use this file except in compliance
+    with the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+
+-->
 <PPP Version="2023-001" TimeStamp="2023-06-09T21:17:14.416+02:00">
   <P1 SubVersion="a1" MID="XX003" PN="156" SL="3"/>
   <P2 SubVersion="b1"><Color>blue</Color></P2>