Bump lxml from 4.6.5 to 4.9.1

Bumps [lxml](https://github.com/lxml/lxml) from 4.6.5 to 4.9.1.
- [Release notes](https://github.com/lxml/lxml/releases)
- [Changelog](https://github.com/lxml/lxml/blob/master/CHANGES.txt)
- [Commits](lxml/lxml@lxml-4.6.5...lxml-4.9.1)

---
updated-dependencies:
- dependency-name: lxml
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -2,6 +2,6 @@ requests==2.27.1
 rdflib==5.0.0
 pandas==0.22.0
 pycld2==0.41
-lxml==4.6.5
+lxml==4.9.1
 beautifulsoup4==4.10.0
 SPARQLWrapper==1.8.5