Disable validation on forms.MultipleChoiceField

fields.py

from django.forms import MultipleChoiceField

class MultipleChoiceAnyField(MultipleChoiceField):
    """A MultipleChoiceField with no validation."""

    def valid_value(self, *args, **kwargs):
        return True

forms.py

from django import forms
from .fields import MultipleChoiceAnyField

class ObjectForm(forms.ModelForm):
    categories = MultipleChoiceAnyField(required=False, \
                                        widget=forms.CheckboxSelectMultiple)
    
    # [...]