Ref T7604. Remove a call to arcanist.projectinfo from arc export. This Conduit call was only used to detect the repository encoding, which we should be able to do locally anyway.
I was considering removing the $projectName from ArcanistBundle as well, but I'm not convinved that this is a good idea. Specifically, doing so would make it difficult to issue the "This patch is for the 'X' project, but the working copy belongs to the 'Y' project" error. We could potentially use the repository callsign for this purposes, but this isn't portable across installs.