Bump lxml from 4.6.3 to 4.6.5

Bumps [lxml](https://github.com/lxml/lxml) from 4.6.3 to 4.6.5.
- [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-4.6.5)

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

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

requirements.txt

@@ -25,7 +25,7 @@ Jinja2==3.0.2
 jmespath==0.10.0
 keras-nightly==2.5.0.dev2021032900
 Keras-Preprocessing==1.1.2
-lxml==4.6.3
+lxml==4.6.5
 Markdown==3.3.4
 MarkupSafe==2.0.1
 mistune==0.8.4