test_argparse leaks references (regression)

[vstinner]

The commit 328dbc0 of gh-85567 introduced a reference leak:

$ ./python -m test --matchfile=bisect -R 3:3 test_argparse 
(...)
test_argparse leaked [24, 24, 24] references, sum=72
(...)

[vstinner]

Fixed by reverting the change: #91771