Update django-import-export requirement in /backend

Updates the requirements on [django-import-export](https://github.com/django-import-export/django-import-export) to permit the latest version.
- [Release notes](https://github.com/django-import-export/django-import-export/releases)
- [Changelog](https://github.com/django-import-export/django-import-export/blob/main/docs/changelog.rst)
- [Commits](django-import-export/django-import-export@3.2.0...4.3.13)

---
updated-dependencies:
- dependency-name: django-import-export
  dependency-version: 4.3.13
  dependency-type: direct:production
...

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

Author: dependabot[bot]

backend/pyproject.toml

@@ -70,7 +70,7 @@ dependencies = [
     "unidecode<2.0.0,>=1.1.1",
     "strawberry-graphql==0.257.0",
     "Werkzeug>=1.0.1,<4.0.0",
-    "django-import-export<4.0.0,>=3.2.0",
+    "django-import-export>=3.2.0,<5.0.0",
     "dal-admin-filters==1.1.0",
     "django-markdownify==0.9.5",
     "django-imagekit==5.0.0",