dependency calculation takes much longer now (e.g. pmbootstrap build postmarketos-ui-plasma-mobile)

Created by: ollieparanoid

Since #935, the dependency resolving got much slower. This is probably, because we check now, if a package's dependencies need to rebuilt or not - and we don't cache it during one session.

This means for meta-packages like plasma-mobile, it will check the same dependencies over and over again, causing it to take minutes to complete, at least on my (rather low-end) laptop.

The fix would be caching the packages we already checked during one session (we already do lots of caching, e.g. for parsed APKBUILDs and that gave us good performance boosts).