Semaphore's value argument

Currently we assume that the semaphore's value must be an integer:
https://github.com/python/typeshed/blob/1af9de664f41b51bd3b71dac349564c5c25df810/stdlib/asyncio/locks.pyi#L88-L93

Generally this is correct, but I had a use case where I wanted to disable the semaphore without restructuring my code, so I used float("inf") as the value to ensure that it never unlocks. This works perfectly fine, because the only operations that value needs to support are:

• Adding 1
• Subtracting 1
• Comparing to 0

The infinity float value does all of these fine. So I therefore wonder if we should make this type be int | Literal[math.inf]? I agree that general floats are not a good idea because they will get below 0 without triggering the wait.

从 stdlib/asyncio/locks.pyi 的第 88-93 行开始，检查 Semaphore 的值注解以及周围的 typeshed 约定。确认 int | Literal[math.inf] 是否表达了受支持的行为，然后运行相关的 typeshed 验证；当该注解接受 infinity 且不会将支持范围扩大到一般 floats 时，即表示完成。