updates

.github/workflows/ci.yaml

@@ -0,0 +1,16 @@
+on: [push, pull_request]
+
+name: Continuous integration
+
+jobs:
+  checks:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v27
+      - uses: icewind1991/attic-action@v1
+        with:
+          name: ci
+          instance: https://cache.icewind.me
+          authToken: "${{ secrets.ATTIC_TOKEN }}"
+      - run: nix flake check --keep-going