[Python] Falcon unification issues

[cirospaciari]

@remittor Thanks for unifying the Falcon code, I really appreciate that and it's the right move for sure. Just opened this issue so we can chat about it.

#8111

This PR has some issues:
Falcon does not need to add Server and Date when using socketify and it adds unnecessary overhead, checking global scope is slow on CPython (but acceptable on PyPy).
The servers should emit these headers or a simple wrapper only on apps that need that to emit this would be a better solution, and fairer with servers that already include this natively.

Performance diffs for socketify WSGI on CPython:
Before: 433,316
After: 356,027

[remittor]

checking global scope is slow on CPython (but acceptable on PyPy).
socketify WSGI on CPython: Before: 433,316 After: 356,027

I think that the drop in speed is not caused by the addition of the common function add_ext_headers.
It is very likely that the drop in speed caused the downgrade of CPython to version 3.9 (previously used version 3.10).

Speeds for Falcon+FastWSGI: before: 497,777 after: 496,506

[cirospaciari]

For socketify CPython can run on 3.11 the latest version (with includes a lot of performance improvements) I think all servers can run on 3.11. ( and soon 3.12)

"Python 3.11 is between 10-60% faster than Python 3.10. On average, we measured a 1.25x speedup on the standard benchmark suite. See Faster CPython for details."

https://docs.python.org/3/whatsnew/3.11.html

PyPy latest is 3.9:

https://www.pypy.org/posts/2022/12/pypy-v7311-release.html

I would upgrade all to latest version and also remove the global lookup + the extra functions calls.

https://wiki.python.org/moin/PythonSpeed/PerformanceTips

Socketify is not a C extension (we use CFFI) so running in the latest CPython is crucial and more realistic, bleeding edge frameworks should use the most recent releases.

[remittor]

I think all servers can run on 3.11. ( and soon 3.12)

I don't mind at all. I just thought that there would be compatibility issues with some modules.
So I suggest you do the following:

1. Convert all falcon tests to python 3.10...3.11.
2. Fix django (since you yourself promised to do it)
3. Help to understand the reason for not started flask + uwsgi (everything works on CI)
4. Help to understand the reason for not working flask test update (everything works on CI)

[cirospaciari]

Agreed, unfortunately, I'm working a lot in my current job, and spending my little free time with my family, soon I should be able to have more time to work on this