Auto merge of #118321 - WaffleLapkin:unspace-fn-pointer-fake-variadic, r=notriddle

rustdoc: Remove space from fake-variadic fn ptr impls

before: `for fn (T₁, T₂, …, Tₙ) -> Ret`
after: `for fn(T₁, T₂, …, Tₙ) -> Ret`

I don't think we usually have spaces there, so it looks weird.

cc `@notriddle` since you added the space in rust-lang/rust#98180 (or rather, added the feature with a space included).

Author: bors