Changes to append! inconpatible with TypedTables.jl

[MasonProtter]

It seems that this commit a20a3d0 (cc @aviatesk) makes append! no longer work with TypedTables.jl

julia> VERSION
v"1.10.0-DEV.1247"

julia> using TypedTables

julia> tints = Table(a = [1], b = [2])
Table with 2 columns and 1 row:
     a  b
   ┌─────
 1 │ 1  2

julia> supertype(typeof(tints))
AbstractVector{@NamedTuple{a::Int64, b::Int64}} (alias for AbstractArray{@NamedTuple{a::Int64, b::Int64}, 1})

julia> append!(tints, [(a=3, b=4)])
ERROR: MethodError: no method matching __inbounds_setindex!(::Table{@NamedTuple{a::Int64, b::Int64}, 1, @NamedTuple{a::Vector{Int64}, b::Vector{Int64}}}, ::@NamedTuple{a::Int64, b::Int64}, ::Int64)

Closest candidates are:
  __inbounds_setindex!(::Array{T}, ::Any, ::Int64) where T
   @ Base array.jl:1019
  __inbounds_setindex!(::Array{T}, ::Any, ::Int64, ::Int64, ::Int64...) where T
   @ Base array.jl:1021

Stacktrace:
 [1] _append!(a::Table{@NamedTuple{a::Int64, b::Int64}, 1, @NamedTuple{a::Vector{Int64}, b::Vector{Int64}}}, ::Base.HasShape{1}, iter::Vector{@NamedTuple{a::Int64, b::Int64}})
   @ Base ./array.jl:1189
 [2] append!(a::Table{@NamedTuple{a::Int64, b::Int64}, 1, @NamedTuple{a::Vector{Int64}, b::Vector{Int64}}}, iter::Vector{@NamedTuple{a::Int64, b::Int64}})
   @ Base ./array.jl:1178
 [3] top-level scope
   @ REPL[24]:1

whereas on earlier versions that worked:

julia> append!(tints, [(a=3, b=4)])
Table with 2 columns and 2 rows:
     a  b
   ┌─────
 1 │ 1  2
 2 │ 3  4

julia> VERSION
v"1.9.0-rc3"

[aviatesk]

Thanks for your report. Submitted a fix at #49754.