* noarch=yes is replaced with archs=noarch
* only_for_archs= is renamed to archs=
* archs= allows the use of wildcards and negations; first matching rule applies:
* archs="*-musl" will build the pkg only for musl-libcs
* archs="~*-musl" will build the pkg only on non-musl-libc
* archs="x86_64-musl ~*-musl" will build for x86_64-musl and any non-musl
arch.
* archs= defaults to "*"