pmbootstrap aportgen: replace arch=all with native
As I'm resolving the 32-bit breakage on postmarketOS edge, I see failing armv7/binutils-aarch64 etc. packages (timeout). So let's get rid of them.
Packages like
binutils-*, busybox-static-*, gcc-*, grub-efi-*, musl-*
are only needed for the native architecture during cross compilation. Don't bother with trying to build them for other arches to save time and to avoid getting stuck frequently at "armv7/binutils-aarch64" etc.
- Close: #1930 (closed)
- Related: build.postmarketos.org#72 (closed)
CI is expected to fail because of missing 32-bit packages.