Context

When we originally created our checkpointer, we were the first to create one as an external contributor. These tests are extensive, and valuable, but also hard to maintain in sync with a moving code base. Vadym had originally suggested that we not include these tests at all but they had served to be valuable at testing corner cases so I decided to keep the tests in 'integration_tests'. At the time, Vadym also said that they planned to release a test package that we could install and run. We don't know where that's at.

Definition of done

1. Get tests green by turning off the failing tests.
2. Organize a meeting with LangGraph folks.
3. Decide how to proceed.
4. Perhaps return to INTPYTHON-488.