Add updated carbon.txt support in API and debugging views. Part of #438

[mrchrisadams]

This PR introduces two changes:

1. add support for carbon.txt in nocache API calls as outlined in [ENHANCEMENT] Adding some support for carbon.txt in our detailed checkers and API involves us  #438
2. removes the use of Redis via a third party library. We don't really use redis any more, and if we did, we'd probably use it via the native library inside the django 4.x