Since abuild 3.16.0_rc1 split functions are executed in $pkgdir. And
built files in build() are no longer showing up in "$srcdir" but are in
$pkgdir now apparently.
[ci:skip-vercheck] # just build fixes, no change in final package
Part-of: <https://gitlab.postmarketos.org/postmarketOS/pmaports/-/merge_requests/7428>