build(deps): bump xmlunit.version from 2.11.0 to 2.12.0

Bumps `xmlunit.version` from 2.11.0 to 2.12.0.

Updates `org.xmlunit:xmlunit-legacy` from 2.11.0 to 2.12.0
- [Release notes](https://github.com/xmlunit/xmlunit/releases)
- [Changelog](https://github.com/xmlunit/xmlunit/blob/main/RELEASE_NOTES.md)
- [Commits](https://github.com/xmlunit/xmlunit/compare/v2.11.0...v2.12.0)

Updates `org.xmlunit:xmlunit-assertj3` from 2.11.0 to 2.12.0
- [Release notes](https://github.com/xmlunit/xmlunit/releases)
- [Changelog](https://github.com/xmlunit/xmlunit/blob/main/RELEASE_NOTES.md)
- [Commits](https://github.com/xmlunit/xmlunit/compare/v2.11.0...v2.12.0)

---
updated-dependencies:
- dependency-name: org.xmlunit:xmlunit-legacy
  dependency-version: 2.12.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: org.xmlunit:xmlunit-assertj3
  dependency-version: 2.12.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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