Bump packaging from 21.2 to 21.3 (#18054)

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: direct:production
  update-type: version-update:semver-minor
...

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

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

Author: dependabot[bot]

news/requirements.txt

@@ -10,7 +10,7 @@ docopt==0.6.2
     # via -r news/requirements.in
 iniconfig==1.0.1
     # via pytest
-packaging==21.2
+packaging==21.3
     # via pytest
 pluggy==0.13.1
     # via pytest