deps(deps): update packaging requirement from >=21.0 to >=26.2

Updates the requirements on [packaging](https://github.com/pypa/packaging) to permit the latest version.
- [Release notes](https://github.com/pypa/packaging/releases)
- [Changelog](https://github.com/pypa/packaging/blob/main/CHANGELOG.rst)
- [Commits](https://github.com/pypa/packaging/compare/21.0...26.2)

---
updated-dependencies:
- dependency-name: packaging
  dependency-version: '26.2'
  dependency-type: direct:production
...

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

docs/requirements.txt

@@ -11,4 +11,4 @@ sphinx-copybutton>=0.5.0
 sphinx-tabs>=3.4.0
 
 # For parsing project dependencies
-packaging>=21.0
+packaging>=26.2