Bump actions/cache from 2 to 3 (#949)

Bumps [actions/cache](https://github.com/actions/cache) from 2 to 3.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v2...v3)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Sam Bull <[email protected]>

.github/workflows/ci.yaml

@@ -24,7 +24,7 @@ jobs:
       with:
         python-version: 3.9
     - name: Cache PyPI
-      uses: actions/cache@v2
+      uses: actions/cache@v3
       with:
         key: pip-lint-${{ hashFiles('requirements-dev.txt') }}
         path: ~/.cache/pip