[4/4] Remove ExecutionPlan.environment_config
Summary: To make it so that an ExecutionPlan can be created without being able to load a PipelineDefinition, replace the small number of methods on ExecutionPlan that require one with a method parameter rather than assuming it exists as state on the class.
Test Plan: Integration
Reviewers: alangenfeld, cdecarolis
Reviewed By: alangenfeld
Differential Revision: https://dagster.phacility.com/D6143