Ensure tags are present

Strangely enough an action with a tag trigger doesn't seem to checkout
the tag. Also see the discussion around annotated tags here:
actions/checkout#290. As such, let's just be
very explicit and get a full git history with all tags as is.

.github/workflows/release.yaml

@@ -13,6 +13,10 @@ jobs:
           username: ${{ secrets.DOCKER_HUB_USERNAME }}
           password: ${{ secrets.DOCKER_HUB_TOKEN }}
       - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - run: |
+          git fetch --tags --force
       - uses: bazelbuild/setup-bazelisk@v1
       - name: Mount bazel cache
         uses: actions/cache@v2