Bump xmlunit-core from 2.8.4 to 2.9.0

Bumps [xmlunit-core](https://github.com/xmlunit/xmlunit) 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:production
  update-type: version-update:semver-minor
...

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

build.gradle

@@ -209,7 +209,7 @@ dependencies {
     testRuntimeOnly group: 'org.apache.logging.log4j', name: 'log4j-core', version: '3.0.0-SNAPSHOT'
     testRuntimeOnly group: 'org.apache.logging.log4j', name: 'log4j-jul', version: '3.0.0-SNAPSHOT'
     testImplementation 'org.mockito:mockito-core:4.3.0'
-    testImplementation 'org.xmlunit:xmlunit-core:2.8.4'
+    testImplementation 'org.xmlunit:xmlunit-core:2.9.0'
     testImplementation 'org.xmlunit:xmlunit-matchers:2.9.0'
     testRuntimeOnly 'com.tngtech.archunit:archunit-junit5-engine:0.22.0'
     testImplementation 'com.tngtech.archunit:archunit-junit5-api:0.22.0'