Remove fa locale from staging (#476)

This removes `fa` as a tested locale from staging. Fixes #476.
I've marked `fa` as blackisted in the locale status doc https://docs.google.com/spreadsheets/d/18dQsatBMlcekK3hc-Zn-Qawq3b6rK_PBek6c2kJxMME/edit#gid=0

@whimboo please review when you get a chance.