Upgrade git-commit-id-maven-plugin 5.0.0 -> 6.0.0 (#635)

See:
- https://github.com/git-commit-id/git-commit-id-maven-plugin/releases/tag/v6.0.0
- git-commit-id/git-commit-id-maven-plugin@v5.0.0...v6.0.0

pom.xml

@@ -570,7 +570,7 @@
                 <plugin>
                     <groupId>io.github.git-commit-id</groupId>
                     <artifactId>git-commit-id-maven-plugin</artifactId>
-                    <version>5.0.0</version>
+                    <version>6.0.0</version>
                     <configuration>
                         <injectAllReactorProjects>true</injectAllReactorProjects>
                         <runOnlyOnce>true</runOnlyOnce>