Fix error in validating complex row-first hvncat

[BioTurboNick]

With the validation logic implemented in #43940 , a complex input can fail in row-first mode:

[[1 2; 3 4] [5; 6]; [7 8] 9;;;]
ERROR: ArgumentError: incompatible shape in element 2
Stacktrace:
 [1] _typed_hvncat_dims(#unused#::Type{Int64}, dims::Tuple{Int64, Int64, Int64}, row_first::Bool, as::Tuple{Matrix{Int64}, Vector{Int64}, Matrix{Int64}, Int64})
   @ Base .\abstractarray.jl:2386
 [2] _typed_hvncat(::Type, ::Tuple{Int64, Int64, Int64}, ::Bool, ::Matrix{Int64}, ::Vararg{Any})
   @ Base .\abstractarray.jl:2361
 [3] _hvncat(::Tuple{Int64, Int64, Int64}, ::Bool, ::Matrix{Int64}, ::Vararg{Any})
   @ Base .\abstractarray.jl:2190
 [4] hvncat(::Tuple{Int64, Int64, Int64}, ::Bool, ::Matrix{Int64}, ::Vararg{Any})
   @ Base .\abstractarray.jl:2186
 [5] top-level scope
   @ REPL[39]:1

# Expected
3×3×1 Array{Int64, 3}:
[:, :, 1] =
 1  2  5
 3  4  6
 7  8  9

This was due to failing to adjust the check for the row first mode. This PR fixes it.

This should probably be backported into 1.8 and 1.7.3 before release.