sync.yml: Avoid hanging on remote servers
sync.yml: Avoid hanging on remote servers

This avoid apt opening interaction dialogs, and it applies the new
  package list before upgrading packages to avoid spurious etckeeper
  commits.

KellerFuchs/admin-tools,hashbang/admin-tools,hashbang/admin-tools,KellerFuchs/admin-tools,singlerider/admin-tools