fix(api): Remove Django pin from uv override-dependencies and upgrade to 5.2.15 (#7755)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: matthewelwell

api/pyproject.toml

@@ -200,7 +200,6 @@ override-dependencies = [
     "dill==0.3.8",
     "distlib==0.3.9",
     "dj-database-url==3.0.1",
-    "django==5.2.14",
     "django-admin-sso==5.2.0",
     "django-axes==8.1.0",
     "django-cockroachdb==4.2",