Do we need warnings for examples in docstrings?

[purva-thakre]

After #459 some of the docstring examples have a Warning block because we want doctest to check the string output or disregard things like whitespace etc.

Noticed in 03adc6c that the doctest options do not show up in the code output.

https://toqito.readthedocs.io/en/latest/autoapi/states/bb84/index.html

This issue is to go through the docstring examples and remove the warnings related to doctest if they do not show up in the documentation.

[purva-thakre]

Looks like the notes where we make doctest compare a string output should be kept in.

Other options related to doctest can be removed. Fixed by db5eeef