Don't awaken or scale pools during daemon shutdown

Summary:
Ref T12298. Currently, we may attempt to un-hibernate or scale-up daemon pools during shutdown, which is silly and counterproductive.

Instead, just shut down.

Test Plan: Ran bin/phd restart, saw stuff shut down more cleanly and consistently.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T12298

Differential Revision: https://secure.phabricator.com/D17551