[Core] add ffmpeg to autotest env

Author: xushengj

.github/workflows/autotest_e2e.yml

@@ -32,6 +32,7 @@ jobs:
       - name: Install test dependencies
         shell: bash
         run: |
+          apt install -y ffmpeg
           python3 -m pip install --upgrade pip
           pip install pytest pytest-xdist pytest-timeout
       - name: Run tests