Add django-jazzmin to list of tox dependencies to get version

To be able to automatically get the version of the installed package of
`django-jazzmin` we need to explicitly install the package as well.

pyproject.toml

@@ -117,6 +117,7 @@ commands =
     {envpython} -m flake8 jazzmin --max-line-length 120
     {envpython} -m pytest
 deps =
+    django-jazzmin  # Installing self to allow automatic getting of `version` which needs `django-jazzmin` to be install to get information about the package.
     flake9
     pytest
     pytest-django