[BUG] Sort m2m fields before comparing them with diff(...) (#271)

* 🐛 Sort m2m fields before comparing them with `diff(...)`

* Add test case and upgrade changelog

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Co-authored-by: Waket Zheng <waketzheng@gmail.com>

aerich/migrate.py

@@ -271,6 +271,10 @@ class Migrate:
                 # m2m fields
                 old_m2m_fields = cast(List[dict], old_model_describe.get("m2m_fields"))
                 new_m2m_fields = cast(List[dict], new_model_describe.get("m2m_fields"))
+                if old_m2m_fields and len(new_m2m_fields) >= 2:
+                    length = len(old_m2m_fields)
+                    field_index = {f["name"]: i for i, f in enumerate(new_m2m_fields)}
+                    new_m2m_fields.sort(key=lambda field: field_index.get(field["name"], length))
                 for action, _, change in diff(old_m2m_fields, new_m2m_fields):
                     if change[0][0] == "db_constraint":
                         continue