dependency: bump maven-gpg-plugin in /sevntu-checkstyle-idea-extension

Bumps [maven-gpg-plugin](https://github.com/apache/maven-gpg-plugin) from 1.6 to 3.0.1.
- [Release notes](https://github.com/apache/maven-gpg-plugin/releases)
- [Commits](apache/maven-gpg-plugin@maven-gpg-plugin-1.6...maven-gpg-plugin-3.0.1)

---
updated-dependencies:
- dependency-name: org.apache.maven.plugins:maven-gpg-plugin
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

sevntu-checkstyle-idea-extension/pom.xml

@@ -143,7 +143,7 @@
           <plugin>
             <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-gpg-plugin</artifactId>
-            <version>1.6</version>
+            <version>3.0.1</version>
             <executions>
               <execution>
                 <id>sign-artifacts</id>