cgi is deprecated as of Python 3.11

[twm]

There are two uses of the cgi module in treq:

1. One use of cgi.parse_header() in treq.content — suggested replacement is email.message.Message
2. One use of cgi.parse_multipart() in treq.test.test_multipart — same suggested replacement

[cjwatson]

For cgi.parse_multipart, treq is likely to be better off using the multipart module from PyPI. email.message is often not quite right for HTTP form data, despite the similar encoding.

[adiroiban]

Does multipart support non-blocking API?
I took a very quick look at the code and I don't see any callback/non-blocking support. Maybe I need to dig deeper.

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I have this code that I am using in prod for my app https://gist.github.com/adiroiban/7f593d6d18113aae797ad081e07f4745 ... but this uses a fork of twisted web with support for replacing the custom content handler

If anyone is interested, I am happy to get something based on this code into twisted ... I also have tests for it.. but have not added them in the gist.