fix: add actions/checkout to release job for gh CLI git context

gh release create requires a local git repository to determine
the remote origin. The release job only downloaded artifacts
without checking out the repo, causing 'fatal: not a git
repository'.

Author: zuhayrb

.github/workflows/release.yml

@@ -113,6 +113,7 @@ jobs:
     needs: build
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v4
       - uses: actions/download-artifact@v4
         with:
           path: _artifacts