Bump platformdirs from 2.5.4 to 4.2.0 in /src

Bumps [platformdirs](https://github.com/platformdirs/platformdirs) from 2.5.4 to 4.2.0.
- [Release notes](https://github.com/platformdirs/platformdirs/releases)
- [Changelog](https://github.com/platformdirs/platformdirs/blob/main/CHANGES.rst)
- [Commits](tox-dev/platformdirs@2.5.4...4.2.0)

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

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

src/requirements.txt

@@ -58,7 +58,7 @@ pathspec==0.12.1
     # via
     #   -r src/requirements.txt
     #   black
-platformdirs==2.5.4
+platformdirs==4.2.0
     # via
     #   -r src/requirements.txt
     #   black