New warning: `'=': conversion from 'unsigned __int64' to 'uint16_t'` in `generated_cases.c.h`

# Bug report

<img width="987" alt="Снимок экрана 2023-10-27 в 08 59 30" src="https://github.com/python/cpython/assets/4660275/8cabd18f-253a-42fd-bca1-770bdc85b60a">


This line was last changed in https://github.com/python/cpython/pull/109095

I will try to fix it right now.


### Linked PRs
* gh-111387