Bump actions/cache from 2.1.7 to 3.0.1

Bumps [actions/cache](https://github.com/actions/cache) from 2.1.7 to 3.0.1.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](https://github.com/actions/cache/compare/v2.1.7...v3.0.1)

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

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/elixir.yml

@@ -39,7 +39,7 @@ jobs:
         with:
           otp-version: ${{ matrix.pair.otp }}
           elixir-version: ${{ matrix.pair.elixir }}
-      - uses: actions/cache@v2.1.7
+      - uses: actions/cache@v3.0.1
         with:
           path: |
             deps