required should be inferred from the return type of a hybrid property

[snstanton]

With a definition like:

@hybrid_property
def is_active(self) -> bool:
    return self.state == 'ACTIVE'

The resulting graphql field type is currently marked Boolean unless overridden by ORMField(). Column properties correctly determine the nullability from the column definition. It seems reasonable to do the same for the hybrid_property based on the declared type. If the return type were bool | None, then it would be optional, otherwise it should be required.