ci: add Apache 2.0 header to junit-platform.properties for licenseTest

Author: jkschneider

rewrite-gradle/src/test/resources/junit-platform.properties

@@ -1 +1,17 @@
+#
+# Copyright 2026 the original author or authors.
+# <p>
+# Licensed 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
+# <p>
+# https://www.apache.org/licenses/LICENSE-2.0
+# <p>
+# 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.
+#
+
 junit.jupiter.extensions.autodetection.enabled=true