Bump lxml from 4.9.2 to 4.9.3 (#1180)

Bumps [lxml](https://github.com/lxml/lxml) from 4.9.2 to 4.9.3.
- [Release notes](https://github.com/lxml/lxml/releases)
- [Changelog](https://github.com/lxml/lxml/blob/master/CHANGES.txt)
- [Commits](lxml/lxml@lxml-4.9.2...lxml-4.9.3)

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

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

requirements/doc.txt

@@ -1,5 +1,5 @@
 Sphinx>=1.7.8
 sphinx-rtd-theme>=0.1.8
 cssselect>=1.0.3
-lxml==4.9.2
+lxml==4.9.3
 zope.testbrowser==6.0