Enable cython 3

[Ericgig]

Description
Ensure qutip works with cython 3.0.

• nogil must come after except.
• Set the options c_api_binop_methods=True to keep previous behaviour of operators.
• Have one of the test case use cython 3.

There is a bug in cython 3.0.0b2 with overflowcheck that makes it unable to compile qutip. I works with 3.0.0.b1 and should work with the next release. See cython#5358

Related issues or PRs
close #2117

[Ericgig]

This require cython>=0.29.32...

[coveralls]

coverage: 84.655%. remained the same when pulling 6e05e97 on Ericgig:misc.cython3 into 5fa0ca6 on qutip:master.

[Ericgig]

cython 3.0.0b3 is out, but another conflict appeared, see cython#5472.

[Ericgig]

@hodgestar
Instead of waiting for the fix to be released in cython, I commented the missing feature: data specializations' __module__.