build(deps): bump org.codehaus.mojo:flatten-maven-plugin

Bumps [org.codehaus.mojo:flatten-maven-plugin](https://github.com/mojohaus/flatten-maven-plugin) from 1.1.0 to 1.6.0.
- [Release notes](https://github.com/mojohaus/flatten-maven-plugin/releases)
- [Commits](mojohaus/flatten-maven-plugin@flatten-maven-plugin-1.1.0...1.6.0)

---
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

@@ -64,7 +64,7 @@
         <opencsv.version>5.9</opencsv.version>
         <testcontainers-bom.version>1.19.8</testcontainers-bom.version>
         <testcontainers-keycloak.version>3.2.0</testcontainers-keycloak.version>
-        <flatten-maven.version>1.1.0</flatten-maven.version>
+        <flatten-maven.version>1.6.0</flatten-maven.version>
         <license-tool.version>1.1.0</license-tool.version>
         <assertj.version>3.24.2</assertj.version>
     </properties>