fix: fallback to docker driver if docker-container fails (sysfs mount perms)

.gitea/actions/docker-build/action.yml

@@ -75,15 +75,18 @@ runs:
         chmod +x $HOME/.docker/cli-plugins/docker-buildx
         docker buildx version
 
-        # Create a builder instance (reuse if exists)
-        docker buildx create \
+        # Try docker-container driver first (for multi-platform), fall back to docker driver
+        if docker buildx create \
           --name gitea-builder \
           --driver docker-container \
           --driver-opt image=moby/buildkit:buildx-stable-1 \
           --driver-opt network=host \
-          --use \
-          2>/dev/null || docker buildx use gitea-builder
+          --use 2>/dev/null; then
+          docker buildx inspect --bootstrap && exit 0
+        fi
 
+        # Fallback: use docker driver (works on all runners, single-platform only)
+        docker buildx create --name gitea-builder --driver docker --use 2>/dev/null || docker buildx use gitea-builder
         docker buildx inspect --bootstrap
 
     - name: Compute metadata