R1:291461344404

Fix failure to record `pullerPHID` in repository pull logs

Summary:
See PHI305. Ref T13046.

The SSH workflows currently extend `PhabricatorManagementWorkflow` to benefit from sharing all the standard argument parsing code. Sharing the parsing code is good, but it also means they inherit a `getViewer()` method which returns the ommnipotent viewer.

This is appropriate for everything else which extends `ManagementWorkflow` (like `bin/storage`, `bin/auth`, etc.) but not appropriate for SSH workflows, which…