Add github workflow for testing flake outputs

.github/workflows/main.yml

@@ -0,0 +1,18 @@
+name: Update Nix Inputs
+
+on:
+  push:
+    branches: [main]
+  schedule:
+    - cron: "0 * * * *" # every hour
+
+jobs:
+  update-inputs:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: DeterminateSystems/nix-installer-action@main
+      - uses: DeterminateSystems/magic-nix-cache-action@main
+
+      - run: nix run .#test