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/python.yml

@@ -33,7 +33,7 @@ jobs:
           echo "::set-output name=dir::$(pip cache dir)"
 
       - name: pip cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{ steps.pip-cache.outputs.dir }}
           key: ${{ runner.os }}-pip-v2-${{ hashFiles('**/setup.py') }}
@@ -46,7 +46,7 @@ jobs:
           pip install tox tox-gh-actions
 
       - name: tox cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: .tox/
           key: ${{ runner.os }}-tox-v2-${{ hashFiles('**/setup.py') }}