Bump actions/cache from 2.1.6 to 2.1.7 (#31)

Bumps [actions/cache](https://github.com/actions/cache) from 2.1.6 to 2.1.7.
- [Release notes](https://github.com/actions/cache/releases)
- [Commits](actions/cache@c64c572...937d244)

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

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/docker.yml

@@ -20,7 +20,7 @@ jobs:
         uses: docker/setup-buildx-action@94ab11c41e45d028884a99163086648e898eed25 # 1.6.0
 
       - name: Cache Docker layers
-        uses: actions/cache@c64c572235d810460d0d6876e9c705ad5002b353 # 2.1.6
+        uses: actions/cache@937d24475381cd9c75ae6db12cb4e79714b926ed # 2.1.6
         with:
           path: /tmp/.buildx-cache
           key: ${{ runner.os }}-buildx-${{ github.sha }}