Bump django-pipeline from 2.1.0 to 3.1.0

Bumps [django-pipeline](https://github.com/jazzband/django-pipeline) from 2.1.0 to 3.1.0.
- [Release notes](https://github.com/jazzband/django-pipeline/releases)
- [Changelog](https://github.com/jazzband/django-pipeline/blob/master/HISTORY.rst)
- [Commits](jazzband/django-pipeline@2.1.0...3.1.0)

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

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

pyproject.toml

@@ -33,7 +33,7 @@ dependencies = [
     "uk-election-ids==0.7.5",
     "uk-election-timetables==2.4.1",
     "uk-geo-utils==0.12.0",
-    "django-pipeline==3.0.0",
+    "django-pipeline==3.1.0",
     "django-dotenv==1.4.2",
     "dc_design_system @ https://github.com/DemocracyClub/design-system/archive/refs/tags/0.5.0.zip",
     "dc_django_utils @ git+https://github.com/DemocracyClub/[email protected]",