subtyping may forget to consider tuple elements

[vtjnash]

julia> T = Tuple{Type{Tuple{}}, Tuple{Vararg{Int8, A}}} where A
Tuple{Type{Tuple{}}, Tuple{Vararg{Int8, A}}} where A

julia> S = Tuple{Type{Tuple{Vararg{Int32, A}}}, Tuple{Vararg{Int16, A}}} where A
Tuple{Type{Tuple{Vararg{Int32, A}}}, Tuple{Vararg{Int16, A}}} where A

julia> T <: S
true

(as trigged by running the offsetarray, arrayops, abstractarray, or missing tests with, extra sanity asserts enabled, it reports this subtyping mistake on: a = Tuple{typeof(Base.convert), Type{Tuple{}}, Tuple{Int64, Vararg{Integer, N}} where N}, b = Tuple{typeof(Base.convert), Type{Tuple{Vararg{Int64, _A}}}, Tuple{Int64, Vararg{Int64, _A}}} where _A))

equivalently:

Tuple{Type{Tuple{}}, Vararg{Int8, A}} where A
S = Tuple{Type{Tuple{Vararg{Int32, A}}}, Vararg{Int16, A}} where A

[JeffBezanson]

Fixed by #31698