fix: use buildah to build

.gitea/workflows/ci.yaml

@@ -21,30 +21,14 @@ jobs:
           nix --extra-experimental-features nix-command --extra-experimental-features flakes build .
           cp -L result result.tar.gz
 
-      - name: Upload image artifact
-        uses: actions/upload-artifact@v3
-        with:
-          name: image
-          path: result.tar.gz
-          retention-days: 7
-
-  push:
-    runs-on: bare-metal
-    needs: build
-    steps:
-      - name: Download image artifact
-        uses: actions/download-artifact@v3
-        with:
-          name: image
-
       - name: Log in to Gitea container registry
-        run: podman login -u ${{ secrets.REGISTRY_USER }} -p ${{ secrets.REGISTRY_PASSWORD }} ${{ env.REGISTRY }}
+        run: buildah login -u ${{ secrets.REGISTRY_USER }} -p ${{ secrets.REGISTRY_PASSWORD }} ${{ env.REGISTRY }}
 
       - name: Push image
         run: |
-          podman load -i result.tar.gz
-          podman tag "localhost/gregs-homepage:latest" ${{ env.IMAGE }}
-          podman push ${{ env.IMAGE }}
+          buildah load -i result.tar.gz
+          buildah tag "localhost/gregs-homepage:latest" ${{ env.IMAGE }}
+          buildah push ${{ env.IMAGE }}
 
   deploy:
     runs-on: blog