build(deps): bump platformdirs from 4.3.7 to 4.3.8

Bumps [platformdirs](https://github.com/tox-dev/platformdirs) from 4.3.7 to 4.3.8.
- [Release notes](https://github.com/tox-dev/platformdirs/releases)
- [Changelog](https://github.com/tox-dev/platformdirs/blob/main/CHANGES.rst)
- [Commits](https://github.com/tox-dev/platformdirs/compare/4.3.7...4.3.8)

---
updated-dependencies:
- dependency-name: platformdirs
  dependency-version: 4.3.8
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements-docs.txt

@@ -170,7 +170,7 @@ pillow==11.2.1
     # via
     #   cairosvg
     #   mkdocs-material
-platformdirs==4.3.7
+platformdirs==4.3.8
     # via
     #   black
     #   mkdocs-get-deps