Try setting-up Buildx; use default image again.

.forgejo/workflows/release.yml

@@ -17,11 +17,12 @@ jobs:
   release:
     name: Release
     runs-on: docker
-    container:
-      image: ubuntu-latest
     steps:
       - name: Checkout the repository
         uses: actions/checkout@v4
+
+      - name: Setup Buildx
+        uses: https://code.forgejo.org/docker/setup-buildx-action@v3
       
       - name: Login to the NibTech Container Registry
         uses: https://code.forgejo.org/docker/login-action@v3