[deps] Update django-reversion requirement from ~=5.0.12 to ~=5.1.0

Updates the requirements on [django-reversion](https://github.com/etianen/django-reversion) to permit the latest version.
- [Release notes](https://github.com/etianen/django-reversion/releases)
- [Changelog](https://github.com/etianen/django-reversion/blob/master/CHANGELOG.rst)
- [Commits](etianen/django-reversion@v5.0.12...v5.1.0)

---
updated-dependencies:
- dependency-name: django-reversion
  dependency-type: direct:production
...

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

requirements-test.txt

@@ -1,3 +1,3 @@
 openwisp-utils[qa,selenium]~=1.1.0
 django-redis~=5.4.0
-django-reversion~=5.0.12
+django-reversion~=5.1.0