Update dependency org.codehaus.mojo:flatten-maven-plugin to v1.7.3 (#12)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

pom.xml

@@ -38,7 +38,7 @@
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>flatten-maven-plugin</artifactId>
-        <version>1.7.2</version>
+        <version>1.7.3</version>
         <configuration>
           <updatePomFile>true</updatePomFile>
           <flattenMode>resolveCiFriendliesOnly</flattenMode>