CI: Add python3-pip to Linux build steps

Author: DeeDeeG

.github/workflows/build.yml

@@ -35,7 +35,7 @@ jobs:
     steps:
     - name: Install build dependencies - Linux
       if: ${{ runner.os == 'Linux' }}
-      run: apt-get update && apt-get install -y git python3 make gcc g++ libx11-dev libxkbfile-dev pkg-config libsecret-1-dev rpm xvfb ffmpeg zstd
+      run: apt-get update && apt-get install -y git python3 python3-pip make gcc g++ libx11-dev libxkbfile-dev pkg-config libsecret-1-dev rpm xvfb ffmpeg zstd
 
     - name: Checkout the latest code
       uses: actions/checkout@v3