Merge branch 'ps/remove-packfile-store-get-packs'

Two slightly different ways to get at "all the packfiles" in API has been cleaned up. * ps/remove-packfile-store-get-packs: packfile: rename `packfile_store_get_all_packs()` packfile: introduce macro to iterate through packs packfile: drop `packfile_store_get_packs()` builtin/grep: simplify how we preload packs builtin/gc: convert to use `packfile_store_get_all_packs()` object-name: convert to use `packfile_store_get_all_packs()`