Update rust.yml

.github/workflows/rust.yml

@@ -35,7 +35,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Install dependencies
-      run: sudo cat deb http://archive.ubuntu.com/ubuntu focal-updates main > /etc/apt/sources.list & sudo apt-get update & sudo apt-get install -y pkg-config cmake clang
+      run: sudo cat deb http://archive.ubuntu.com/ubuntu focal-updates main > /etc/apt/sources.list & sudo apt-get update & sudo apt-get install -y pkg-config cmake clang libgtk-3-dev
     - uses: actions/checkout@v3
     - name: Install latest nightly
       uses: actions-rs/toolchain@v1