dont re-raise errors caught by pipeline failure
Now that PipelineFailure has the exception captured - I don't think there is a reason to re-raise it by default.
This also helps a bit with work to move resource init out of the run orchestrator
Test Plan: bk
Reviewers: cdecarolis, dgibson
Reviewed By: cdecarolis
Differential Revision: https://dagster.phacility.com/D7412