Bump flatten-maven-plugin from 1.2.2 to 1.2.3

Bumps [flatten-maven-plugin](https://github.com/mojohaus/flatten-maven-plugin) from 1.2.2 to 1.2.3.
- [Release notes](https://github.com/mojohaus/flatten-maven-plugin/releases)
- [Commits](mojohaus/flatten-maven-plugin@flatten-maven-plugin-1.2.2...flatten-maven-plugin-1.2.3)

Signed-off-by: dependabot-preview[bot] <[email protected]>

pom.xml

@@ -1285,7 +1285,7 @@
           <plugin>
             <groupId>org.codehaus.mojo</groupId>
             <artifactId>flatten-maven-plugin</artifactId>
-            <version>1.2.2</version>
+            <version>1.2.3</version>
             <configuration>
               <updatePomFile>true</updatePomFile>
             </configuration>