R1:7f6fa283639f

When loading packages affected by a change to a particular path, ignore archived packages

Summary:
Ref T11650. Currently, we load packages and then discard the archived ones.

However, this gets "dominion" rules (where a more-general package gives up ownership if a more-specific package exists) wrong if the more-specific package is archived: we incorrectly give up ownership.

Instead, just ignore these packages completely when loading affected packages. This is slightly simpler.

(There are technically…