[bug#66424] [PATCH core-updates] gnu: libxkbcommon: Fix cross-compile.

[zhengjunjie]

> 在 2023年10月13日，22:50，Maxim Cournoyer <maxim.cournoyer@gmail.com> 写道：
> 
> 
> On the top of my head, I thought pkg-config-for-build had been obsolete
> by the pkg-config symbol being dynamically bound to something that makes
> sense for the context it's used in, via some macro trickery.  I may have
> misunderstood things

For cross build, 

pkg-config -> xxxx-pkg-config
pkg-config-for-build -> pkg-config

libxkbcommon require wayland-scanner to generate c file, this is why need 
pkg-config-for-build, pkg-config is require by find library. Is different ,so 
libxkbcommon need both on cross build.