Fix the function, so it does not crash anymore when the
replace_subpkgnames argument is set and a dependency cannot be resolved.
Instead, print a useful warning that shows which pmaport caused the
error (that has always been a pain to figure out), and simply don't
replace the potential subpkgname with the real pkgname, just use the
dependency name as-is.
Resolve annoying crashes in bpo dependency resolving, like this one
(caused by a few linux-* pmaports for bad downstream kernels that depend
on python, not apparent at all from the message):
[09:08:15] Calculate packages that need to be built (all packages, aarch64)
[09:08:26] ERROR: Package 'python': Could not find aport, and could not find this package in any APKINDEX!
Related: https://builds.sr.ht/~postmarketos/job/184022
b18ec9a693