argparse option argument with `nargs=argparse.REMAINDER` is misplaced in usage line

Bug report

When using an optional argument with nargs=argparse.REMAINDER, the argument appears within the list of optional arguments and before any positional arguments. I expected it to be placed last in usage line, which would better match the behavior since it consumes any following parameters. Not sure it is really bug...

The following scripts shows the issue:

#!/usr/bin/env python

import argparse

parser = argparse.ArgumentParser()
parser.add_argument('foo')
parser.add_argument('--extra', nargs=argparse.REMAINDER)
parser.add_argument('--option')

args = parser.parse_args()

[--extra ...] is not at all last in the usage line:

$ ./test.py -h
usage: test.py [-h] [--extra ...] [--option OPTION] foo

positional arguments:
  foo

options:
  -h, --help       show this help message and exit
  --extra ...
  --option OPTION

Your environment

• archlinux/amd64
• Tested on python 3.10.4 and also on 3.7.7 and 3.8.7.

Run the minimal argparse script from the report and inspect how ArgumentParser formats its usage line for add_argument calls using nargs=argparse.REMAINDER. Confirm the current ordering and identify the relevant argparse usage-formatting tests or entry point. Done means the remainder option appears after positional arguments in usage output without disturbing other option ordering.