fix: add ffmpeg installer for fluentmpeg

[miltoncandelero]

42

This happens if you don't have ffmpeg installed in your path:

@ffmpeg-installer should solve this

https://www.npmjs.com/package/@ffmpeg-installer/ffmpeg?activeTab=readme

const ffmpegPath = require('@ffmpeg-installer/ffmpeg').path;
const ffmpeg = require('fluent-ffmpeg');
ffmpeg.setFfmpegPath(ffmpegPath);

[miltoncandelero]

The automated tests install ffmpeg on the container and that's why this error didn't pop earlier.

We should fix the github actions but I needed this fix to come out ASAP 😅

[Zyie]

I broke this PR by trying to fix the merge conflict so just added the changes directly to main 🤣

thanks for helping out with this @miltoncandelero