Bump django-modelcluster from 6.4 to 6.4.1 (#5149)

Bumps [django-modelcluster](https://github.com/wagtail/django-modelcluster) from 6.4 to 6.4.1.
- [Release notes](https://github.com/wagtail/django-modelcluster/releases)
- [Changelog](https://github.com/wagtail/django-modelcluster/blob/main/CHANGELOG.txt)
- [Commits](wagtail/django-modelcluster@v6.4...v6.4.1)

---
updated-dependencies:
- dependency-name: django-modelcluster
  dependency-version: 6.4.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -151,7 +151,7 @@ django-leaflet==0.19.post11
     # via mapentity
 django-maintenance-mode==0.22.0
     # via geotrek (setup.py)
-django-modelcluster==6.4
+django-modelcluster==6.4.1
     # via geotrek (setup.py)
 django-modeltranslation==0.19.17
     # via mapentity