chore(deps): bump flatten-maven-plugin from 1.3.0 to 1.4.0

Bumps [flatten-maven-plugin](https://github.com/mojohaus/flatten-maven-plugin) from 1.3.0 to 1.4.0.
- [Release notes](https://github.com/mojohaus/flatten-maven-plugin/releases)
- [Commits](https://github.com/mojohaus/flatten-maven-plugin/compare/flatten-maven-plugin-1.3.0...1.4.0)

---
updated-dependencies:
- dependency-name: org.codehaus.mojo:flatten-maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...
Signed-off-by: dependabot[bot] <support@github.com>

pom.xml

@@ -106,7 +106,7 @@
         <xxl-job.version>2.0.2</xxl-job.version>
 
         <!-- maven plugins -->
-        <flatten-maven-plugin.version>1.3.0</flatten-maven-plugin.version>
+        <flatten-maven-plugin.version>1.4.0</flatten-maven-plugin.version>
         <integration-maven-plugin.version>${revision}</integration-maven-plugin.version>
         <maven.repository.url>https://maven.schbrain.com/repository</maven.repository.url>
     </properties>