Bump version.xmlunit from 2.8.4 to 2.9.0 (#246)

Bumps `version.xmlunit` from 2.8.4 to 2.9.0.

Updates `xmlunit-core` from 2.8.4 to 2.9.0
- [Release notes](https://github.com/xmlunit/xmlunit/releases)
- [Changelog](https://github.com/xmlunit/xmlunit/blob/main/RELEASE_NOTES.md)
- [Commits](xmlunit/xmlunit@v2.8.4...v2.9.0)

Updates `xmlunit-matchers` from 2.8.4 to 2.9.0
- [Release notes](https://github.com/xmlunit/xmlunit/releases)
- [Changelog](https://github.com/xmlunit/xmlunit/blob/main/RELEASE_NOTES.md)
- [Commits](xmlunit/xmlunit@v2.8.4...v2.9.0)

---
updated-dependencies:
- dependency-name: org.xmlunit:xmlunit-core
  dependency-type: direct:development
  update-type: version-update:semver-minor
- dependency-name: org.xmlunit:xmlunit-matchers
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pom.xml

@@ -62,7 +62,7 @@
     <version.jackson>2.13.1</version.jackson>
 
     <version.junit-jupiter>5.8.2</version.junit-jupiter>
-    <version.xmlunit>2.8.4</version.xmlunit>
+    <version.xmlunit>2.9.0</version.xmlunit>
     <version.jsonassert>1.5.0</version.jsonassert>
   </properties>