Inherit Meta.ordering from abstract base models (#2046)

[uttam12331]

Summary

Closes #2046.

When a model defines its own Meta (for example to set table) but does not set ordering, the ordering declared on an abstract base model's Meta was silently dropped, so queries on the subclass came back unordered:

class BaseModel(Model):
    created_at = fields.DatetimeField(auto_now_add=True)
    class Meta:
        ordering = ["-created_at"]
        abstract = True

class Book(BaseModel):
    name = fields.CharField(max_length=255)
    class Meta:
        table = "books"

await Book.all()   # not ordered by -created_at

Root cause

ModelMeta.__new__ builds the model's MetaInfo from attrs.get("Meta", ...) — i.e. only the class's own Meta. When the subclass supplies its own Meta without ordering, the abstract base's ordering is never consulted.

Fix

After building the meta, if the subclass's own Meta does not define ordering, inherit the default ordering from the first base model that has one. This mirrors how abstract-base Meta options behave in similar ORMs.

Behavior is preserved for models that:

• define their own ordering (theirs wins), or
• define an explicitly empty ordering = [] (stays empty).

Tests

Added test_abstract_meta_ordering_is_inherited, covering inheritance, own-ordering-wins, and explicit-empty-stays-empty. It fails on develop and passes with this change. Existing test_inheritance.py / test_order_by.py still pass; ruff check/ruff format are clean; added a CHANGELOG entry.