`sys.set_asyncgen_hooks` docs are not correct about its signature

[sobolevn]

Bug report

Refs #103132 (comment)

The signature is set_asyncgen_hooks(firstiter=<unrepresentable>, finalizer=<unrepresentable>).
Docs say that it is: set_asyncgen_hooks(firstiter, finalizer)
Docstring say that it is: set_asyncgen_hooks(* [, firstiter] [, finalizer])

It should be: set_asyncgen_hooks([firstiter] [, finalizer]) (I guess)

Linked PRs

• gh-114384: Fix sys.set_asyncgen_hooks signature in docs #114385
• [3.12] gh-114384: Align sys.set_asyncgen_hooks signature in docs to reflect implementation (GH-114385) #114386
• [3.11] gh-114384: Align sys.set_asyncgen_hooks signature in docs to reflect implementation (GH-114385) #114387