Bump packaging from 20.9 to 21.0

Bumps [packaging](https://github.com/pypa/packaging) from 20.9 to 21.0.
- [Release notes](https://github.com/pypa/packaging/releases)
- [Changelog](https://github.com/pypa/packaging/blob/main/CHANGELOG.rst)
- [Commits](pypa/packaging@20.9...21.0)

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

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

Author: dependabot[bot]

docs-requirements.txt

@@ -22,9 +22,9 @@ jinja2==2.11.3
     # via sphinx
 markupsafe==1.1.1
     # via jinja2
-packaging==20.9
+packaging==21.0
     # via sphinx
-pygments==2.8.1
+pygments==2.9.0
     # via sphinx
 pyparsing==2.4.7
     # via packaging
@@ -46,7 +46,7 @@ sphinxcontrib-jsmath==1.0.1
     # via sphinx
 sphinxcontrib-qthelp==1.0.3
     # via sphinx
-sphinxcontrib-serializinghtml==1.1.4
+sphinxcontrib-serializinghtml==1.1.5
     # via sphinx
 urllib3==1.26.6
     # via requests

test-requirements.txt

@@ -36,15 +36,15 @@ lxml==4.6.3
     # via -r test-requirements.in
 markupsafe==1.1.1
     # via jinja2
-packaging==20.9
+packaging==21.0
     # via
     #   pytest
     #   sphinx
 pluggy==0.13.1
     # via pytest
 py==1.10.0
     # via pytest
-pygments==2.8.1
+pygments==2.9.0
     # via sphinx
 pyparsing==2.4.7
     # via packaging
@@ -72,7 +72,7 @@ sphinxcontrib-jsmath==1.0.1
     # via sphinx
 sphinxcontrib-qthelp==1.0.3
     # via sphinx
-sphinxcontrib-serializinghtml==1.1.4
+sphinxcontrib-serializinghtml==1.1.5
     # via sphinx
 toml==0.10.2
     # via pytest