chore(deps): bump django-import-export from 2.7.1 to 4.2.1

Bumps [django-import-export](https://github.com/django-import-export/django-import-export) from 2.7.1 to 4.2.1.
- [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@2.7.1...4.2.1)

---
updated-dependencies:
- dependency-name: django-import-export
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

base-requirements.txt

@@ -49,7 +49,7 @@ num2words==0.5.13
 django-polymorphic==3.1.0  # 3.1.0 is first version that supports Django 4.0, unsure if it fully supports 4.2
 sorl-thumbnail==12.11.0
 django-extensions==3.2.3
-django-import-export==2.7.1
+django-import-export==4.2.1
 
 pypandoc==1.12
 panflute==2.3.1