sagemathgh-40341: Set cython directive `binding=True`
    
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Continuation of sagemath#26254. This is needed for better integration of Cython
functions and thereby unlocks a few further documentation improvements
(sagemath#27578, sagemath#30884, sagemath#31309, ...).

Moreover, `binding=True` is the default in Cython 3.

### 📝 Checklist


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### ⌛ Dependencies

- sagemath#40357
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URL: sagemath#40341
Reported by: Tobias Diez
Reviewer(s): David Coudert