Restore the ability to toggle unsigned addons in firefox?

[Unit193]

Howdy,

It seems there's actually a way to toggle this back on, and while not a good idea for typical use it's great if you want to try out a change before making a PR on GitHub.

I found this bug report on Gentoo0, and this older and terrible script1 and after trying something like that, was able to add an unsigned test addon in firefox 100.0.2.

Perhaps this should come with a large warning, but it'd be quite useful!

Thanks so much for this script, it makes firefox much more usable.