[5.0.x] Applied Black's 2024 stable style.

https://github.com/psf/black/releases/tag/24.1.0

Backport of 305757aec1 from main

tests/m2m_intermediary/models.py

@@ -9,6 +9,7 @@ each ``Article``-``Reporter`` combination (a ``Writer``) has a ``position``
 field, which specifies the ``Reporter``'s position for the given article
 (e.g. "Staff writer").
 """
+
 from django.db import models