Install makedepends in native chroot for packages using Rust

The changes in pmaports!4234 cause cargo build scripts to be built
for and run on the host (native) architecture, so their dependencies
must be present in the native chroot.

pmbootstrap can't tell which of the dependencies specified in
makedepends are actually needed by build scripts, so just duplicate all
of them in the native chroot.

Acked-by: Caleb Connolly <kc@postmarketos.org>
Reviewed-by: Oliver Smith <ollieparanoid@postmarketos.org>
Link: https://lists.sr.ht/~postmarketos/pmbootstrap-devel/%3C20230710135001.184769-1-otto.pflueger@abscue.de%3E

pmb/build/init.py

@@ -108,6 +108,6 @@ def init_compiler(args, depends, cross, arch):
     if cross == "crossdirect":
         cross_pkgs += ["crossdirect"]
         if "rust" in depends or "cargo" in depends:
-            cross_pkgs += ["rust"]
+            cross_pkgs += depends
 
     pmb.chroot.apk.install(args, cross_pkgs)