Remove daemon envHash and envInfo

Summary: Ref T7053. Remove the envHash and envInfo fields, which are no longer used now that the daemons restart automagically. Depends on D14458.

Test Plan: Saw no more setup issues.

Reviewers: Blessed Reviewers, epriestley

Reviewed By: Blessed Reviewers, epriestley

Subscribers: tycho.tatitscheff, epriestley

Maniphest Tasks: T7053

Differential Revision: https://secure.phabricator.com/D14446