Bump lxml from 4.5.2 to 4.6.1

Bumps [lxml](https://github.com/lxml/lxml) from 4.5.2 to 4.6.1.
- [Release notes](https://github.com/lxml/lxml/releases)
- [Changelog](https://github.com/lxml/lxml/blob/master/CHANGES.txt)
- [Commits](lxml/lxml@lxml-4.5.2...lxml-4.6.1)

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

requirements.txt

@@ -1,5 +1,5 @@
 ansible>=2.8.0
 graphviz==0.14.1
 colour==0.1.5
-lxml==4.5.2
+lxml==4.6.1
 packaging==20.4