Extra newlines added before function with fmt skip on decorator

[JelleZijlstra]

    I've just tested this out with a medium-sized codebase. All as expected apart from this one issue with a comment at the end of a function getting 2 newlines added above it. Removing `@decorator1` stops the comment getting moved, as does removing `# fmt:skip`.

https://black.vercel.app/?version=stable&state=_Td6WFoAAATm1rRGAgAhARYAAAB0L-Wj4ADZAIZdAD2IimZxl1N_WlbvK5V9KEd0suDTtKdXyoIEqib4HPPAOaGeijv-QM5F2CIWMxNomuS8WtfuVtc-CBav7wmp196mwOSJGXUmaRTdIwYr1wf881xD3biQ1s52KZSzb20ApVmRJ9HPRaEOhoVMkb9jDbRHrld5-g2LTBdcrPwjnT90_-ZGPvMAAAAAsri7GeyV3k8AAaIB2gEAAEJ-yuKxxGf7AgAAAAAEWVo=

Originally posted by @jgillard in #3407 (comment)

[JelleZijlstra]

I tested this out and it happens only if both of the decorators on bar are present and the second one has # fmt: skip.

Copy-pastable sample:

def foo():
    pass
    # Comment on next below

@decorator1
@decorator2  # fmt: skip
def bar():
    pass

[yilei]

This has the same underlying issue as #3438, I'll take a look this week.