Deprecate (and eventually remove) `tp_is_gc`

Feature or enhancement

Proposal:

The existence of tp_is_gc slows down and complicates allocation, deallocation and garbage collection.

But there is no need for it, as statically allocated objects can be marked as immortal as will be ignored by the GC.
I doubt there is much third-party code that uses it, if any.

We should deprecate it, and then remove it.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

首先定位 CPython 中 tp_is_gc 的定義及所有使用位置，然後檢查靜態配置的物件如何被標記為 immortal，以及垃圾回收器如何處理這些物件。確定棄用和最終移除的範圍，包括對第三方擴充功能相容性的影響。當提議的替代方案得到驗證，並且棄用或移除得到一致實作時，即視為完成。