MinValueValidator and MaxValueValidator accept NaN

[Aathithya Arasu S]

Both validators accept float NaN without raising an error:

from django.core.validators import MinValueValidator, MaxValueValidator

MinValueValidator(0)(float("nan"))  # no error
MaxValueValidator(10)(float("nan"))  # no error

A model FloatField with MinValueValidator(0) also passes full_clean() with NaN. This seems inconsistent with forms.FloatField, which rejects it. Is rejecting NaN in these validators the intended behavior too?

I have a patch that checks a != a before the existing comparison, with regression tests. It also changes quiet Decimal NaN from an InvalidOperation exception to a ValidationError. Valid infinity comparisons stay unchanged.

Reproduced on main (6.2.dev, commit ca3f31b) and 5.2.19.