Make Job.statepoint read only. #983
Description
Feature description
Provide one API to access the job statepoint.
Proposed solution
Make Job.statepoint read only with the same performance benefits of cached_statepoint introduced in #975. cached_statepoint would then no longer be needed.
Job.update_statepoint then becomes the only method to change a job's statepoint.
Additional context
This is a breaking change and would require significant changes to the signac documentation and unit tests in a major release.