Bump maven-gpg-plugin from 1.6 to 3.0.1

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>

pom.xml

@@ -32,7 +32,7 @@
         <jacoco-maven-plugin.version>0.8.7</jacoco-maven-plugin.version>
         <maven-source-plugin.version>3.2.1</maven-source-plugin.version>
         <nexus-staging-maven-plugin.version>1.6.7</nexus-staging-maven-plugin.version>
-        <maven-gpg-plugin.version>1.6</maven-gpg-plugin.version>
+        <maven-gpg-plugin.version>3.0.1</maven-gpg-plugin.version>
         <git.repository>cardano-community/koios-java-client</git.repository>
     </properties>