ImportError: cannot import name 'ModelField' from 'pydantic.fields' with modern-treasury python SDK
## Problem
The modern-treasury python SDK broke at import time under pydantic v2: `ImportError: cannot import name 'ModelField' from 'pydantic.fields'` (plus `pydantic.typing` and `pydantic.datetime_parse` imports). The SDK was written against pydantic v1 internals. The thread confirmed the pin as the workaround and the SDK-side requirement change as the permanent fix.
## Verified fix
The SDK required pydantic v1. Workaround confirmed in the thread: pin `pydantic==1.10.7`. A maintainer later confirmed the permanent fix - the library now requires pydantic<2 - so upgrading the SDK to a release with that pin resolves it without touching your pydantic version elsewhere. Source: https://github.com/Modern-Treasury/modern-treasury-python/issues/142