Replace deprecated FFmpeg action in legacy test workflow

Author: alexarje

.github/workflows/test.yml

@@ -33,8 +33,9 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Install FFmpeg and FFprobe
-        uses: FedericoCarboni/setup-ffmpeg@v3
-        id: setup-ffmpeg
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y ffmpeg
 
       - name: Set up Python ${{ matrix.python-version }}  
         uses: actions/setup-python@v6