Plug.Conn.Query has changed the way it decodes parameters from 1.14 to 1.15 without warning

Plug used to be able to decode lists of maps the obvious way, but now it doesn't anymore. Example code:

defmodule PlugRegression do
  alias Plug.Conn.Query

  def test() do
    params = """
    a[][id]=1&\
    a[][id]=2&\
    a[][id]=3&\
    a[][id]=4&\
    """

    reordered_params = """
    a[][id]=3&\
    a[][id]=1&\
    a[][id]=2&\
    a[][id]=4&\
    """

    decoded = Query.decode(params)
    decoded_reordered = Query.decode(reordered_params)

    IO.puts("\nDecoded parameters:")
    IO.puts("─────────────────────────────")
    IO.inspect(decoded)
    IO.puts("─────────────────────────────\n")
    IO.puts("Decoded parameters after reordering:")
    IO.puts("─────────────────────────────")
    IO.inspect(decoded_reordered)
    IO.puts("─────────────────────────────\n")
  end
end

Result from running the code with Plug 1.14.0:

iex(18)> Application.spec(:plug)[:vsn]
'1.14.0'
iex(19)> PlugRegression.test

Decoded parameters:
─────────────────────────────
%{"a" => [%{"id" => "1"}, %{"id" => "2"}, %{"id" => "3"}, %{"id" => "4"}]}
─────────────────────────────

Decoded parameters after reordering:
─────────────────────────────
%{"a" => [%{"id" => "3"}, %{"id" => "1"}, %{"id" => "2"}, %{"id" => "4"}]}
─────────────────────────────

:ok

Result from running the code with Plug 1.15.0:

iex(2)> Application.spec(:plug)[:vsn]
'1.15.0'
iex(3)> PlugRegression.test()        

Decoded parameters:
─────────────────────────────
%{"a" => [%{"id" => "4"}]}
─────────────────────────────

Decoded parameters after reordering:
─────────────────────────────
%{"a" => [%{"id" => "4"}]}
─────────────────────────────

:ok

This breaks some code I'm using in practice (and even if it didn't, I don't think this behaviour should change from 1.14 to 1.15 because it's totally backward-incompatible)

elixir-plug / plug

Plug.Conn.Query has changed the way it decodes parameters from 1.14 to 1.15 without warning #1182