Bump actions/cache from 3 to 4

Bumps [actions/cache](https://github.com/actions/cache) from 3 to 4.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v3...v4)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/django.yml

@@ -40,7 +40,7 @@ jobs:
       # The one above caches the wheel files, but still runs the installation for them
       # While the cache below caches the entire Python directory.
       - name: Cache pip
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: /opt/hostedtoolcache/Python/3.10.8/x64/ # This path is specific to Ubuntu
           key: python-${{ hashFiles('requirements/local.txt') }}-${{ hashFiles('requirements/base.txt') }}