Fix test_sync_list_container_grpc running locally outside of BK
Summary:
- Cache the docker image locally so the test doesn't take a bunch of time every time it runs locally (with a message with a command to run to invalidate it, like the other docker tests)
- Fix an errant contextmanager that was causing the docker container to never spin up when the test runs outside of BK
Test Plan: Run api_tests locally, no longer gets stuck on this test
Reviewers: sashank, alangenfeld
Differential Revision: https://dagster.phacility.com/D4973