Autorelease: Add missing checkout

Author: ewjoachim

.github/workflows/release.yml

@@ -21,6 +21,9 @@ jobs:
       attestations: write
       id-token: write
     steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3