Bump lxml from 4.9.0 to 4.9.1 (#3319)

Bumps [lxml](https://github.com/lxml/lxml) from 4.9.0 to 4.9.1.
- [Release notes](https://github.com/lxml/lxml/releases)
- [Changelog](https://github.com/lxml/lxml/blob/master/CHANGES.txt)
- [Commits](https://github.com/lxml/lxml/compare/lxml-4.9.0...lxml-4.9.1)

---
updated-dependencies:
- dependency-name: lxml
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements.txt

@@ -5,7 +5,7 @@ flask-babel==2.0.0
 flask==2.1.1
 jinja2==3.1.2
 langdetect==1.0.9
-lxml==4.9.0
+lxml==4.9.1
 pygments==2.8.0
 python-dateutil==2.8.2
 pyyaml==6.0