[bug#72959] Request for merging "fonts-split-outputs" branch

[宋文武]

I think the branch is ready once it built on CI.

>From https://issues.guix.gnu.org/70496:

Hello, here are some patches for font packages which updates
the install phase in font-build-system for multiple outputs, and
use that for some font packages.

When a font family is provided in different formats (eg: both ttf and
otf), font picker will list duplicated entries.  To remove those
duplicated entries, these patches will prefer "otf" over "ttf" files
by using '("out" "ttf")) as package's outputs field, so that otf files
will go into the default "out" output.