New comment by Zapeth on void-packages repository

https://github.com/void-linux/void-packages/pull/41060#issuecomment-1363216129

Comment:
I managed to make some space on my machine and was able to build `firefox-esr` and `firefox-esr-i18n` (the only issue I came across was a language entry not being ordered correctly which caused checksum issues, but thats fixed now)

I also had to update my system packages due to the recent gcc update, but after that I was able to use the new version (briefly tested it, updated description)

> @Zapeth Looking over the template I cant find that files/mozconfig is being sourced anymore, can we stop vendoring it since add_options are defined in template?

I think so, yes. I compared the add_options and the only difference I found was that `--enable-system-ffi` is now set with `--with-system-ffi`. I don't know which of the two should be set, but I'd keep the latter since its also used in the normal firefox package.

So I went ahead and removed it, and rebased again