fix an edge constructor bug in LinearIndices

[johnnychen94]

An edge case bug that gets Identified in #37829 (comment)

Integers should always be converted to Base.OneTo.

julia> LinearIndices((2, 1:3))
1×3 LinearIndices{2, Tuple{UnitRange{Int64}, UnitRange{Int64}}}:
 1  2  3

julia> LinearIndices((2, 3))
2×3 LinearIndices{2, Tuple{Base.OneTo{Int64}, Base.OneTo{Int64}}}:
 1  3  5
 2  4  6

This PR:

julia> LinearIndices((2, 1:3))
2×3 LinearIndices{2, Tuple{Base.OneTo{Int64}, Base.OneTo{Int64}}}:
 1  3  5
 2  4  6

[timholy]

Thanks!