Update django requirement from <5.0 to <6.0

Updates the requirements on [django](https://github.com/django/django) to permit the latest version.
- [Commits](django/django@1.0...5.1.2)

---
updated-dependencies:
- dependency-name: django
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

pyproject.toml

@@ -8,7 +8,7 @@ dependencies = [
     "blurhash-python>=1.2.2",
     "cachetools>=5.5.0",
     "dateparser>=1.2.0",
-    "django<5.0",
+    "django<6.0",
     "django-anymail>=12.0",
     "django-auditlog>=3.0.0",
     "django-bleach>=3.1.0",