Skip some repository checks in cluster enviornments
Summary:
Ref T2783. Currently, the repository edit page does some checks agaisnt the local system to look for binaries and files on disk. These checks don't make sense in a cluster environment.
Ideally, we could make a Conduit call to the host (e.g., add something like `diffusion.querysetupstatus`) to do these checks, but since they're pretty basic config things and cluster installs are advanced, it doesn't seem super worthwhile for now.
Test Plan: Saw fewer checks in a cluster repo.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T2783
Differential Revision: https://secure.phabricator.com/D11102