gh-95468: Fixes issue with ArgumentParser skipping '--' options

[PurityLake]

Fixes #95468

ArgumentParser does not pass over '--' characters when nargs is set to *, + or ... now.

Example program:

import argparse

for nargs in [ '+', '*', '...' ]:
    p = argparse.ArgumentParser()
    p.add_argument('arg1', type=str)
    p.add_argument('args', nargs=nargs)
    p.add_argument('arg2', type=str)
    print(p.parse_args(['foo', '--', '--bar', '--', 'com', "last"]))

• Issue: argparse.ArgumentParser silently swallows multiple -- (double dash) #95468