Upgrading Redis on Heroku causing SSL errors in Celery

I've recently upgraded our Heroku Redis from version 5.0 to 7.0.11 and I'm now receiving the following error when running Celery

 Traceback (most recent call last):
   File "/app/.heroku/python/bin/celery", line 8, in <module>
     sys.exit(main())
   File "/app/.heroku/python/lib/python3.8/site-packages/celery/__main__.py", line 15, in main
     sys.exit(_main())
   File "/app/.heroku/python/lib/python3.8/site-packages/celery/bin/celery.py", line 235, in main
     return celery(auto_envvar_prefix="CELERY")
   File "/app/.heroku/python/lib/python3.8/site-packages/click/core.py", line 1130, in __call__
     return self.main(*args, **kwargs)
   File "/app/.heroku/python/lib/python3.8/site-packages/click/core.py", line 1055, in main
     rv = self.invoke(ctx)
   File "/app/.heroku/python/lib/python3.8/site-packages/click/core.py", line 1657, in invoke
     return _process_result(sub_ctx.command.invoke(sub_ctx))
   File "/app/.heroku/python/lib/python3.8/site-packages/click/core.py", line 1404, in invoke
     return ctx.invoke(self.callback, **ctx.params)
   File "/app/.heroku/python/lib/python3.8/site-packages/click/core.py", line 760, in invoke
     return __callback(*args, **kwargs)
   File "/app/.heroku/python/lib/python3.8/site-packages/click/decorators.py", line 26, in new_func
     return f(get_current_context(), *args, **kwargs)
   File "/app/.heroku/python/lib/python3.8/site-packages/celery/bin/base.py", line 134, in caller
     return f(ctx, *args, **kwargs)
   File "/app/.heroku/python/lib/python3.8/site-packages/celery/bin/worker.py", line 348, in worker
     worker = app.Worker(
   File "/app/.heroku/python/lib/python3.8/site-packages/celery/worker/worker.py", line 98, in __init__
     self.setup_instance(**self.prepare_args(**kwargs))
   File "/app/.heroku/python/lib/python3.8/site-packages/celery/worker/worker.py", line 119, in setup_instance
     self._conninfo = self.app.connection_for_read()
   File "/app/.heroku/python/lib/python3.8/site-packages/celery/app/base.py", line 818, in connection_for_read
     return self._connection(url or self.conf.broker_read_url, **kwargs)
   File "/app/.heroku/python/lib/python3.8/site-packages/celery/app/base.py", line 877, in _connection
     return self.amqp.Connection(
   File "/app/.heroku/python/lib/python3.8/site-packages/kombu/connection.py", line 203, in __init__
     url_params = parse_url(hostname)
   File "/app/.heroku/python/lib/python3.8/site-packages/kombu/utils/url.py", line 50, in parse_url
     query['ssl'][key] = query[key]
 TypeError: 'str' object does not support item assignment

celery.py

from celery import Celery

app = Celery('endpoints')

# namespace='CELERY' means all celery-related configuration keys should have a `CELERY_` prefix.
app.config_from_object('django.conf:settings', namespace='CELERY')
app.conf.redis_backend_use_ssl = {
                 'ssl_cert_reqs': 'CERT_NONE'
            }
app.conf.broker_use_ssl = {
                 'ssl_cert_reqs': 'CERT_NONE'
            }

# Load task modules from all registered Django app configs.
app.autodiscover_tasks()

requirements.txt

dj-database-url==2.0.0
Django==4.2.2
django-environ==0.9.0
django-storages==1.9.1
djangorestframework==3.14.0
django-cors-headers==3.5.0
django-parler==2.3
redis==4.5.5
celery[redis]==5.3.0

Everything was working flawlessly prior to the upgrade, but this error is causing celery to crash immediately.