Only download APKINDEX for relevant architectures
Created by: ollieparanoid
We're downloading the APKINDEX files for all architectures supported by postmarketOS currently (x86, x86_64, armhf, aarch64). Most of the time, we only need it for the native and device arch, so this PR reduces the downloaded files to what is really necessary.
This PR gives pmb.helpers.repo.update()
a new optional arch
parameter, and uses that parameter wherever possible.