add update step

.github/workflows/linux.yml

@@ -20,6 +20,8 @@ jobs:
     - uses: actions/checkout@v4
     - name: Run rustfmt
       run: cargo fmt --all -- --check
+    - name: Update packages index
+      run: sudo apt update
     - name: Install system packages
       run: sudo apt install -y libgtk-4-dev libgtksourceview-5-dev libadwaita-1-dev libspelling-1-dev libsqlite3-dev
     - name: Run clippy