fix: add build dependencies for CI

.github/workflows/rust.yml

@@ -19,6 +19,10 @@ jobs:
       with:
         apt: libpango1.0-dev libgtk-4-dev
 
+    - uses: KyleMayes/install-llvm-action@v1
+      with:
+        version: "16.0"
+
     - uses: actions/checkout@v3
     - name: Build
       run: cargo build --verbose