Bump actions/cache from 2 to 3

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]>

.github/workflows/workflow.yaml

@@ -21,7 +21,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Mount Bazel cache
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: ~/repo-cache
           key: repo-cache-${{ runner.os }}-nixpkgs-${{ env.cache-version }}