add build images workflow

.gitea/workflows/build-images.yml

@@ -0,0 +1,18 @@
+name: Build Images
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  check:
+    runs-on: nixos-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Build Image
+        run: nix build .#dockerImages.aarch64-linux.node