ci: build nix packages

.gitea/workflows/build.yml

@@ -0,0 +1,25 @@
+name: Build packages
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  build-packages:
+    strategy:
+      matrix:
+        package:
+          - "default"
+    runs-on: nix
+    steps:
+      - uses: https://github.com/cachix/cachix-action@v14
+        with:
+          name: ysyx
+          authToken: '${{ secrets.CACHIX_SIGNING_KEY }}'
+      - uses: actions/checkout@v4
+      - name: Build package
+        run: |
+          nix build -L .#${{ matrix.package }}