Ensure Maven plugin descriptor inputs are out-of-date on version change

Closes gh-22766

Author: wilkinsona

buildSrc/src/main/java/org/springframework/boot/build/mavenplugin/MavenPluginPlugin.java

@@ -177,6 +177,7 @@ private Copy createCopyPluginDescriptorInputs(Project project, File destination,
 		pluginDescriptorInputs.from(pomFile, (copy) -> replaceVersionPlaceholder(copy, project));
 		pluginDescriptorInputs.from(sourceSet.getOutput().getClassesDirs(), (sync) -> sync.into("target/classes"));
 		pluginDescriptorInputs.from(sourceSet.getAllJava().getSrcDirs(), (sync) -> sync.into("src/main/java"));
+		pluginDescriptorInputs.getInputs().property("version", project.getVersion());
 		return pluginDescriptorInputs;
 	}