Owners - sort repositories alphabetically in path chooser

Summary: Fixes T6834. Without this asort() call, repositories are ordered by ID, which is arbitrary to the user. This sorts them alphabetically by callsign.

Test Plan: edited a package and saw repos sorted by call sign

Reviewers: epriestley, chad

Reviewed By: chad

Subscribers: Korvin, epriestley

Maniphest Tasks: T6834

Differential Revision: https://secure.phabricator.com/D11095