ci: add rust and nix jobs

.github/workflows/nix.yml

@@ -0,0 +1,24 @@
+name: Nix
+on: [push, pull_request]
+
+jobs:
+  build:
+    name: Check flake and upload build cache
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v22
+        with:
+          github_access_token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Setup Cachix
+        uses: cachix/cachix-action@v13
+        with:
+          name: mrnossiom
+          authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+
+      - name: Check flake structure
+        run: nix flake check
+
+      - name: Build nix package
+        run: nix build --print-build-logs

.github/workflows/rust.yml

@@ -0,0 +1,20 @@
+name: Rust
+on: [push, pull_request]
+
+jobs:
+  check:
+    name: Check and test Rust code
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt, clippy
+
+      - name: Cache Rust dependencies
+        uses: Swatinem/rust-cache@v2
+
+      - run: cargo check
+      - run: cargo test
+      - run: cargo fmt --all -- --check
+      - run: cargo clippy -- -D warnings