Try to fetch tags with the GitHub action checkout

By default, this GitHub action doesn't retrieve the tags of the current
branch but we need to get these tags for `dune-release`.

.github/workflows/release.yml

@@ -17,6 +17,7 @@ jobs:
         uses: actions/checkout@v3
         with:
           persist-credentials: false
+          fetch-tags: true
 
       - name: Use OCaml ${{ env.OCAML_DEFAULT_VERSION }}
         uses: ocaml/setup-ocaml@v2