Bump lxml from 4.6.3 to 4.9.1

Bumps [lxml](https://github.com/lxml/lxml) from 4.6.3 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-4.6.3...lxml-4.9.1)

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

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

Author: dependabot[bot]

mmdl.egg-info/requires.txt

@@ -1,7 +1,7 @@
 ytmusicapi==0.18.0
 youtube_dl==2021.6.6
 click_help_colors==0.9.1
-lxml==4.6.3
+lxml==4.9.1
 click==8.0.1
 youtube_search_python==1.4.6
 eyed3==0.9.6

requirements.txt

@@ -1,7 +1,7 @@
 ytmusicapi==0.18.0
 youtube_dl==2021.6.6
 click_help_colors==0.9.1
-lxml==4.6.3
+lxml==4.9.1
 click==8.0.1
 youtube_search_python==1.4.6
 eyed3==0.9.6