build(deps-dev): bump lxml from 5.1.0 to 5.2.1

Bumps [lxml](https://github.com/lxml/lxml) from 5.1.0 to 5.2.1.
- [Release notes](https://github.com/lxml/lxml/releases)
- [Changelog](https://github.com/lxml/lxml/blob/master/CHANGES.txt)
- [Commits](lxml/lxml@lxml-5.1.0...lxml-5.2.1)

---
updated-dependencies:
- dependency-name: lxml
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

requirements-dev.txt

@@ -1,7 +1,7 @@
 Babel==2.14.0
 flake8==7.0.0
 furo==2024.1.29
-lxml==5.1.0
+lxml==5.2.1
 m2r2==0.3.3.post2
 numpydoc==1.6.0
 kodi-addon-checker==0.0.31