[maven-release-plugin] prepare release maven-site-plugin-3.21.0

pom.xml

@@ -28,7 +28,7 @@ under the License.
   </parent>
 
   <artifactId>maven-site-plugin</artifactId>
-  <version>3.20.1-SNAPSHOT</version>
+  <version>3.21.0</version>
   <packaging>maven-plugin</packaging>
 
   <name>Apache Maven Site Plugin</name>
@@ -174,7 +174,7 @@ under the License.
   <scm>
     <connection>scm:git:https://gitbox.apache.org/repos/asf/maven-site-plugin.git</connection>
     <developerConnection>scm:git:https://gitbox.apache.org/repos/asf/maven-site-plugin.git</developerConnection>
-    <tag>HEAD</tag>
+    <tag>maven-site-plugin-3.21.0</tag>
     <url>https://github.com/apache/maven-site-plugin/tree/${project.scm.tag}</url>
   </scm>
   <issueManagement>
@@ -213,7 +213,7 @@ under the License.
     <antrunPluginVersion>3.1.0</antrunPluginVersion>
     <mavenReportingImplVersion>4.0.0</mavenReportingImplVersion>
     <fluidoSkinVersion>2.0.0-M11</fluidoSkinVersion>
-    <project.build.outputTimestamp>2024-08-14T15:58:15Z</project.build.outputTimestamp>
+    <project.build.outputTimestamp>2024-10-18T12:10:28Z</project.build.outputTimestamp>
   </properties>
 
   <dependencies>