Clean up the dtrace code and documentation for the hook is not using

[Zheaoli]

Bug report

Bug description:

8 years ago, @ambv add dtrace support in CPython in a785c87

For now, after check the code, I think the point following below is not used in CPython code

• function__entry
• function__return
• instance__new__start
• instance__new__done
• instance__delete__start
• instance__delete__done
• line

I think we need to clean up the code and the document in https://docs.python.org/3/howto/instrumentation.html

cc @markshannon

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-125914: Clean up the dtrace code and documentation for the hook is not using #126246