Bring back the Ubuntu CI builds

After adding extra dependencies, that build job turns green again

This is basically a revert of 5a215c1

.github/workflows/ci-build.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [windows-latest, macos-latest]
+        os: [ubuntu-latest, windows-latest, macos-latest]
 
     steps:
     - name: Checkout code
@@ -27,6 +27,17 @@ jobs:
         target: ${{ matrix.os == 'windows-latest' && 'x86_64-pc-windows-msvc' || 'x86_64-unknown-linux-gnu' || 'x86_64-apple-darwin' }}
         components: clippy
 
+    - name: Install Linux dependencies
+      if: matrix.os == 'ubuntu-latest'
+      run: |
+        sudo apt update
+        sudo apt install -y software-properties-common
+        sudo add-apt-repository universe
+        echo "deb http://archive.ubuntu.com/ubuntu $(lsb_release -sc)-backports main restricted universe multiverse" | sudo tee -a /etc/apt/sources.list
+        sudo apt update
+        sudo apt install -y libgtk-3-dev build-essential pkg-config libglib2.0-dev libsoup-3.0-dev libwebkit2gtk-4.1-dev
+        echo "PKG_CONFIG_PATH=/usr/lib/x86_64-linux-gnu/pkgconfig" >> $GITHUB_ENV
+
     - name: Check formatting
       run: cargo fmt -- --check