`reducedim1` removed from Base

[adienes]

this line now fails

Statistics.jl/src/Statistics.jl

Line 288 in e14c8f8

if Base.reducedim1(R, A)

after
JuliaLang/julia#62554

[felixcremer]

It was not fully removed from Base, but the signature was changed to reducedim1(R).
Do we need to take care of backwards compatibility here or can we just make this change directly?

[adienes]

I think I would just make the change. this is not a public function so it shouldn't have been relied on in the first place.