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 的定义及所有使用位置，然后检查静态分配的对象如何被标记为 immortal，以及垃圾回收器如何处理这些对象。确定弃用和最终移除的范围，包括对第三方扩展兼容性的影响。当拟议的替代方案得到验证，并且弃用或移除得到一致实现时，即视为完成。