Update lxml requirement from <5.0,>=4.6.3 to >=4.6.3,<6.0 (#1021)

Updates the requirements on [lxml](https://github.com/lxml/lxml) to permit the latest version.
- [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-5.0.0)

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

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

requirements.txt

@@ -10,7 +10,7 @@ django-rest-knox>=4.1.0,<5.0
 django-filter>=2.2.0,<24.0
 gunicorn>=19.9.0,<22.0
 importlib-metadata==4.13.0
-lxml>=4.6.3,<5.0
+lxml>=4.6.3,<6.0
 markdown>=3.2.2,<4.0
 numpy>=1.18.4,<2.0
 pandas>=1.0.3,<3.0