Support releasing from different branch (#249)

* ci: support releasing from different branch
* fix: git tags are not fetched

This preveted to detect if a `LIB_TAG` is already there.

Signed-off-by: Julian Strobl <jmastr@mailbox.org>

.github/workflows/release.yaml

@@ -25,6 +25,14 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v3
+        with:
+          ref: ${{ github.ref_name }}
+
+      - name: Fetch tags
+        run: |
+          # Cannot use `fetch-tags: true` due to:
+          # https://github.com/actions/checkout/issues/1471
+          git fetch --prune --unshallow --tags
 
       - name: Tag
         run: |