build(deps): bump django-filter upper bound to <26, resolving to 25.1 (#52)

Raise the version ceiling from <25 to <26 so the resolver can pull in
django-filter 25.1.  Version 25.2 is excluded automatically because it
requires Django >= 5.2 while this project pins Django 5.1.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: marevol

backend/pyproject.toml

@@ -12,7 +12,7 @@ dependencies = [
     "django-cors-headers>=4.6,<5",
     "django-extensions>=3.2,<4",
     "django-storages>=1.14,<2",
-    "django-filter>=24.3,<25",
+    "django-filter>=24.3,<26",
     "djangorestframework>=3.15,<4",
     "djangorestframework-simplejwt>=5.3,<6",
     "dj-rest-auth>=7.0,<8",