Support for Valkey

[Zerotask]

Valkey is an open source drop-in replacement for Redis.

Although the scheme redis:// is compatible, the package django-valkey recommends switching to valkey://.

If I change the BROKER_URL from BROKER_URL=redis://127.0.0.1:6379 to BROKER_URL=valkey://127.0.0.1:6379, both celery and celery-beat stops working, because they can't resolve transport:

  File "/***/lib/python3.13/site-packages/kombu/connection.py", line 201, in __init__
    if not get_transport_cls(transport).can_parse_url:
           ~~~~~~~~~~~~~~~~~^^^^^^^^^^^
  File "/***/lib/python3.13/site-packages/kombu/transport/__init__.py", line 91, in get_transport_cls
    _transport_cache[transport] = resolve_transport(transport)
                                  ~~~~~~~~~~~~~~~~~^^^^^^^^^^^
  File "/***/lib/python3.13/site-packages/kombu/transport/__init__.py", line 72, in resolve_transport
    raise KeyError(f'No such transport: {transport}')
KeyError: 'No such transport: valkey'