The strawberry mypy plugin has been removed. It is no longer needed thanks to
@dataclass_transform, overloaded signatures, and the StrawberryTypeFromPydantic
protocol.
If you still have strawberry.ext.mypy_plugin in your mypy configuration, it will
emit a DeprecationWarning and can be safely removed. Pydantic users only need
the pydantic.mypy plugin.
Releases contributed by @bellini666 via #4258