[tests] Set fast_finish: true
[tests] Set fast_finish: true

Immediately finish build once one of the jobs fails to decrease test time

Bug: T186323
Change-Id: I7131fd0bb74029088673c01c2ee0f9725efcff36

wikimedia/pywikibot-core,PersianWikipedia/pywikibot-core,wikimedia/pywikibot-core