add rust clippy workflow

.github/workflows/rust.yml

@@ -0,0 +1,24 @@
+name: Rust
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Rust Cache
+      uses: Swatinem/rust-cache@v2.7.7
+      with:
+        workspaces: "backend"
+        cache-all-crates: "true"
+    - name: Clippy
+      working-directory: backend
+      run: cargo clippy --all-features --all-targets -- -Dwarnings -Dclippy::pedantic