pmb.build: always init cross compiler stuff

Seems to fix the following situation:

1) multiple pkgs to be built

2) 1st package uses crossdirect

3) 2nd package is 'native' (e.g. kernel package w/ pmb:cross-native, which needs gcc-aarch64)

4) 2nd package fails because the cross compiler stuff isn't set up

pmb/build/_package.py

@@ -606,13 +606,11 @@ def packages(
         if src:
             pkg_depends.append("rsync")
 
-        # We only need to init cross compiler stuff once
-        if not cross:
-            cross = pmb.build.autodetect.crosscompile(pkg["apkbuild"], pkg_arch)
-            if cross:
-                pmb.build.init_compiler(context, pkg_depends, cross, pkg_arch)
-            if cross == "crossdirect":
-                pmb.chroot.mount_native_into_foreign(chroot)
+        cross = pmb.build.autodetect.crosscompile(pkg["apkbuild"], pkg_arch)
+        if cross:
+            pmb.build.init_compiler(context, pkg_depends, cross, pkg_arch)
+        if cross == "crossdirect":
+            pmb.chroot.mount_native_into_foreign(chroot)
 
         if not strict and "pmb:strict" not in pkg["apkbuild"]["options"] and len(pkg_depends):
             pmb.chroot.apk.install(pkg_depends, chroot, build=False)