Adding test for ffmpeg

Author: raivisdejus

.github/workflows/ci.yml

@@ -70,6 +70,9 @@ jobs:
           architecture: 'x64'
           github-token: ${{ github.server_url == 'https://github.com' && github.token || '' }}
 
+      - name: Test ffmpeg
+        run: ffmpeg -i ./testdata/audio-long.mp3 ./testdata/audio-long.wav
+
       - name: Install dependencies
         run: poetry install