fix: update maven-gpg-plugin to version 3.1.0

Author: felix-seifert

pom.xml

@@ -320,7 +320,7 @@
                     <plugin>
                         <groupId>org.apache.maven.plugins</groupId>
                         <artifactId>maven-gpg-plugin</artifactId>
-                        <version>1.6</version>
+                        <version>3.1.0</version>
                         <executions>
                             <execution>
                                 <id>sign-artifacts</id>