Use SPDX license header.

dev/checkstyle/header.txt

@@ -1,14 +1,3 @@
 ^/\*$
 ^ \* Copyright [\d]{4}((,[\s]*[\d]{4})*|(-[\d]{4})?) C Thing Software$
-^ \*$
-^ \* 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$
-^ \*$
-^ \*     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\.$
+^ \* PDX-License-Identifier: Apache-2.0$

src/main/java/org/cthing/gradle/plugins/versioning/VersioningPlugin.java

@@ -1,17 +1,6 @@
 /*
  * Copyright 2024 C Thing Software
- *
- * 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
- *
- *     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.
+ * PDX-License-Identifier: Apache-2.0
  */
 
 package org.cthing.gradle.plugins.versioning;

src/main/java/org/cthing/gradle/plugins/versioning/package-info.java

@@ -1,17 +1,6 @@
 /*
  * Copyright 2024 C Thing Software
- *
- * 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
- *
- *     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.
+ * PDX-License-Identifier: Apache-2.0
  */
 
 /**

src/test/java/org/cthing/gradle/plugins/versioning/PluginApplyTest.java

@@ -1,17 +1,6 @@
 /*
  * Copyright 2024 C Thing Software
- *
- * 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
- *
- *     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.
+ * PDX-License-Identifier: Apache-2.0
  */
 
 package org.cthing.gradle.plugins.versioning;

src/test/java/org/cthing/gradle/plugins/versioning/PluginIntegTest.java

@@ -1,17 +1,6 @@
 /*
  * Copyright 2024 C Thing Software
- *
- * 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
- *
- *     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.
+ * PDX-License-Identifier: Apache-2.0
  */
 
 package org.cthing.gradle.plugins.versioning;