Error if data becomes more stale than model start

[eakmanrq]

If a model has data loaded in it that is less than the model start date then we get an error like this:

ValueError: `end` (2023-10-04 00:00:00+00:00) must be greater than `start` (2023-10-07 00:00:00+00:00)

This is likely low impact since it shouldn't really happen in practice.