[tests] Only find one alternative script with script_tests.py
[tests] Only find one alternative script with script_tests.py

utils.execute_pwb imports pwb and pywikibot and config variable cannot
be set directly for that environment and will be ignored. To set the
pwb_close_matches variable use the global argument handling.

This partly reverts change-ID I90d9243

Bug: T296204
Change-Id: If737765748115bc93770945832ab76999bd5e92b

wikimedia/pywikibot-core,wikimedia/pywikibot-core