Bump org.codehaus.mojo:flatten-maven-plugin from 1.5.0 to 1.6.0

Bumps [org.codehaus.mojo:flatten-maven-plugin](https://github.com/mojohaus/flatten-maven-plugin) from 1.5.0 to 1.6.0.
- [Release notes](https://github.com/mojohaus/flatten-maven-plugin/releases)
- [Commits](mojohaus/flatten-maven-plugin@1.5.0...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>

api/pom.xml

@@ -244,7 +244,7 @@ Use is subject to <a href="{@docRoot}/doc-files/speclicense.html" target="_top">
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>flatten-maven-plugin</artifactId>
-                <version>1.5.0</version>
+                <version>1.6.0</version>
                 <configuration>
                     <flattenMode>ossrh</flattenMode>
                 </configuration>