Automatic yt-dlp updates

[gabrielh-so]

Problem

I've found that old yt-dlp versions do not work in a month after they're released as YouTube finds a way to exclude that version from downloading. It's easy enough to fix:

• fetch the most recent release
• or delete the old version and allow the program to download the dependency automatically

but it is tedious/less technically-capable users may find it difficult.

Solution

An enhancement that solves this problem is an optional update-check/download feature that compares the hashes of the latest release and the locally stored executable, and fetches the latest release if they do not match. This reduces the knowledge required to update the dependency. I can make a pr for my fork branch if you'd like.