YT Shorts quality is not the best

[denyshon]

Describe the bug
YouTube Shorts quality is not the best available.

To Reproduce
To reproduce, just download any YT Short with the bot.

Additional context
The issue is caused by yt-dlp. Usually, the best-quality video comes without audio, while the module looks for one with audio. To fix this, we need to download the audio separately and then merge the video and the audio.

[denyshon]

It's priority-low since the bug is minor, only one feature is affected and the fix may be complicated.