TOML: Dict inside mixed vector produces invalid TOML

[fonsp]

julia> import TOML

julia> d =  Dict("b" => Any[Dict("a" =>  222, "d" => 333)]);

julia> TOML.print(d)
[[b]]
a = 222
d = 333

julia> d =  Dict("b" => Any[111, Dict("a" =>  222, "d" => 333)]);

julia> TOML.print(d)
b = [111, a = 222
d = 333
]

This is invalid TOML syntax.

---

It looks like we have code to prevent mixing Dicts and other types in a vector, but it only throws an error if the first element is a Dict:

julia> d =  Dict("b" => Any[Dict("f" => 000), 111, Dict("a" =>  222, "d" => 333)]);

julia> TOML.print(d)
[[b]]
f = 0
[[b]]
ERROR: array should contain only tables
Stacktrace:
 [1] error(s::String)
   @ Base ./error.jl:33
 [2] _print(f::Nothing, io::Base.TTY, a::Dict{String, Vector{Any}}, ks::Vector{String}; indent::Int64, first_block::Bool, sorted::Bool, by::Function)
   @ TOML.Internals.Printer /Applications/Julia-1.7 x86.app/Contents/Resources/julia/share/julia/stdlib/v1.7/TOML/src/print.jl:160
 [3] #print#13
   @ /Applications/Julia-1.7 x86.app/Contents/Resources/julia/share/julia/stdlib/v1.7/TOML/src/print.jl:168 [inlined]
 [4] print(a::Dict{String, Vector{Any}}; sorted::Bool, by::Function)
   @ TOML.Internals.Printer /Applications/Julia-1.7 x86.app/Contents/Resources/julia/share/julia/stdlib/v1.7/TOML/src/print.jl:171
 [5] print(a::Dict{String, Vector{Any}})
   @ TOML.Internals.Printer /Applications/Julia-1.7 x86.app/Contents/Resources/julia/share/julia/stdlib/v1.7/TOML/src/print.jl:171
 [6] top-level scope
   @ REPL[7]:1