Mono vs. Gecko packaging discrepancies

[Vincent Povirk (they/them)]

I've pushed some changes to the master branch. The build artifacts for
Wine Mono 5.0, when it's ready, will be as follows:

wine-mono-5.0.0-src.tar.xz
wine-mono-5.0.0-x86.tar.xz
wine-mono-5.0.0-x86.msi

If and when there is an arm version, it will have "arm" in the
filename instead of x86. There will be no x86_64 or aarch64 downloads
because both 32-bit and 64-bit files will be included in a single
download.

That's going to mean updating addons.c and winemono.php on the website.