Bump org.apache.maven.plugins:maven-gpg-plugin from 1.5 to 3.1.0

Bumps [org.apache.maven.plugins:maven-gpg-plugin](https://github.com/apache/maven-gpg-plugin) from 1.5 to 3.1.0.
- [Commits](apache/maven-gpg-plugin@maven-gpg-plugin-1.5...maven-gpg-plugin-3.1.0)

---
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] <[email protected]>

Author: dependabot[bot]

OCPP-J/pom.xml

@@ -130,7 +130,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-gpg-plugin</artifactId>
-                <version>1.5</version>
+                <version>3.1.0</version>
                 <executions>
                     <execution>
                         <id>sign-artifacts</id>

ocpp-common/pom.xml

@@ -131,7 +131,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-gpg-plugin</artifactId>
-                <version>1.5</version>
+                <version>3.1.0</version>
                 <executions>
                     <execution>
                         <id>sign-artifacts</id>

ocpp-v1_6/pom.xml

@@ -129,7 +129,7 @@
             <plugin>
               <groupId>org.apache.maven.plugins</groupId>
               <artifactId>maven-gpg-plugin</artifactId>
-              <version>1.5</version>
+              <version>3.1.0</version>
               <executions>
                 <execution>
                   <id>sign-artifacts</id>

ocpp-v2/pom.xml

@@ -139,7 +139,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-gpg-plugin</artifactId>
-                <version>1.5</version>
+                <version>3.1.0</version>
                 <executions>
                     <execution>
                         <id>sign-artifacts</id>