TypedModelMeta only allows `list[str]` for `ordering`

[HansAarneLiblik]

Hi!

TypedModelMeta.ordering currently only allows a Sequence of str, but accoding to the docs, expressions like OrderBy should also be allowed

Example of valid input:

class Entry(models.Model):
  type = models.CharField(max_length=100)
  item = models.CharField(max_length=100, null=True)

  class Meta(TypedModelMeta):
    ordering = ["type", F("item").asc(nulls_first=True)]

[intgr]

Yes. Are you interested in submitting a PR? 😆