Background

See T403559: Add CommunityRequests tables to production for context.

We are trying to reduce the number of tables we add, and this one we never truly needed. The idea was we wanted to be able to find wishes with a given task ID, but is no such search or filter currently on our roadmap. If and when we do need to search by task ID, we could instead query the Core iwlinks table to search for phab on wish pages (since our extension requires use of the interwiki prefix). But let's ignore that for now :)

The simple solution for now is to change the "Phabricator tasks" field to be a wikitext field.

Acceptance criteria

• Adding, editing, and saving Phabricator tasks should work just as before, as well as fetching them via ApiQueryWishes
• Drop the communityrequests_phab_tasks table