Basic rust CI instead of nix flake check

.forgejo/workflows/build.yaml

@@ -0,0 +1,30 @@
+on: [push]
+jobs:
+  build:
+    runs-on: beefcake
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+    - name: cargo build
+      run: 'nix develop -c cargo build'
+  test:
+    runs-on: beefcake
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+    - name: cargo test
+      run: 'nix develop -c cargo test'
+  formatting:
+    runs-on: beefcake
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+    - name: cargo fmt --check
+      run: 'nix develop -c cargo fmt --check'
+  lint:
+    runs-on: beefcake
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+    - name: cargo clippy
+      run: 'nix develop -c cargo clippy'