Bump packaging from 21.2 to 21.3

Bumps [packaging](https://github.com/pypa/packaging) from 21.2 to 21.3.
- [Release notes](https://github.com/pypa/packaging/releases)
- [Changelog](https://github.com/pypa/packaging/blob/main/CHANGELOG.rst)
- [Commits](pypa/packaging@21.2...21.3)

---
updated-dependencies:
- dependency-name: packaging
  dependency-type: indirect
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

docs-requirements.txt

@@ -22,7 +22,7 @@ jinja2==3.0.2
     # via sphinx
 markupsafe==2.0.1
     # via jinja2
-packaging==21.2
+packaging==21.3
     # via sphinx
 pygments==2.10.0
     # via sphinx

test-requirements.txt

@@ -36,7 +36,7 @@ lxml==4.6.4
     # via -r test-requirements.in
 markupsafe==2.0.1
     # via jinja2
-packaging==21.2
+packaging==21.3
     # via
     #   pytest
     #   sphinx