Will be nice to have an option to pass custom code for ValidationError based on name of UniqueTogether constraint as it's unique or better to useviolation_error_code .
Line to fix:Link to the line for fix - here is is hard coded tocode='unique'

Example:

class Pet(models.Model):    name = models.CharField(max_length=100)    animal_type = models.CharField(max_length=100)    owner_name = models.CharField(max_length=100)    class Meta:        constraints = [            UniqueConstraint(                fields=["name", "animal_type"],                name="unique_pet",                violation_error_code="unique_pet",            ),            UniqueConstraint(                fields=["owner_name", "animal_type"],                name="unique_pet_type",                violation_error_code="unique_pet_type",            ),        ]

If there are 2 different constraints there is no way to distinguish errors to know which constraint failed as all errors always have code unique and look like:
[{'non_field_errors': [ErrorDetail(string='The fields name, animal_type must make a unique set.', code='unique')]}]
For codename attr of constraint can be used. And error could looks like:
[{'non_field_errors': [ErrorDetail(string='The fields name, animal_type must make a unique set.', code='unique_pet_type')]}]