Merge branch 'jt/sha1-file-remove-oi-skip-cached' into maint

has_object_file() said "no" given an object registered to the system via pretend_object_file(), making it inconsistent with read_object_file(), causing lazy fetch to attempt fetching an empty tree from promisor remotes. * jt/sha1-file-remove-oi-skip-cached: sha1-file: remove OBJECT_INFO_SKIP_CACHED