Handle the case where the connection to redis instances use Sentinels in get_scheduler_statistics()

[alaouimehdi1995]

When using Sentinels connection to Redis instead of a "single host", when displaying the views.stats view, the following exception is raised:

Traceback (most recent call last):
  File "/usr/local/lib/python3.11/site-packages/django/core/handlers/exception.py", line 55, in inner
    response = get_response(request)
               ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django/core/handlers/base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django/views/decorators/cache.py", line 62, in _wrapper_view_func
    response = view_func(request, *args, **kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django/contrib/auth/decorators.py", line 23, in _wrapper_view
    return view_func(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django_rq/views.py", line 37, in stats
    **get_scheduler_statistics(),
      ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django_rq/utils.py", line 106, in get_scheduler_statistics
    conn_key = f"{connection['host']}:{connection.get('port', 6379)}/{connection.get('db', 0)}"
                  ^^^^^^^^^^^^^^^^^^

Exception Type: KeyError at /admin/background-tasks/
Exception Value: 'host'

The current pull request solves the issue by adding condition on the type of ConnectionPool to redis, then fetching connection_kwargs accordingly.

Created issue: #672

[selwin]

Thanks!