[maven-release-plugin] prepare release maven-gpg-plugin-3.1.0

pom.xml

@@ -28,7 +28,7 @@ under the License.
   </parent>
 
   <artifactId>maven-gpg-plugin</artifactId>
-  <version>3.1.0-SNAPSHOT</version>
+  <version>3.1.0</version>
   <packaging>maven-plugin</packaging>
 
   <name>Apache Maven GPG Plugin</name>
@@ -41,7 +41,7 @@ under the License.
   <scm>
     <connection>scm:git:https://gitbox.apache.org/repos/asf/maven-gpg-plugin.git</connection>
     <developerConnection>scm:git:https://gitbox.apache.org/repos/asf/maven-gpg-plugin.git</developerConnection>
-    <tag>HEAD</tag>
+    <tag>maven-gpg-plugin-3.1.0</tag>
     <url>https://github.com/apache/maven-gpg-plugin/tree/${project.scm.tag}</url>
   </scm>
   <issueManagement>
@@ -62,7 +62,7 @@ under the License.
   <properties>
     <mavenVersion>3.2.5</mavenVersion>
     <javaVersion>8</javaVersion>
-    <project.build.outputTimestamp>2021-05-05T16:39:01Z</project.build.outputTimestamp>
+    <project.build.outputTimestamp>2023-05-03T01:33:27Z</project.build.outputTimestamp>
     <resource.delimiter>@</resource.delimiter>
   </properties>