Bump xmlunit-core from 2.3.0 to 2.7.0

Bumps [xmlunit-core](https://github.com/xmlunit/xmlunit) from 2.3.0 to 2.7.0.
- [Release notes](https://github.com/xmlunit/xmlunit/releases)
- [Changelog](https://github.com/xmlunit/xmlunit/blob/main/RELEASE_NOTES.md)
- [Commits](xmlunit/xmlunit@v2.3.0...v2.7.0)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

modello-plugins/modello-plugin-xdoc/pom.xml

@@ -35,7 +35,7 @@
     <dependency>
       <groupId>org.xmlunit</groupId>
       <artifactId>xmlunit-core</artifactId>
-      <version>2.3.0</version>
+      <version>2.7.0</version>
       <scope>test</scope>
     </dependency>
   </dependencies>