This PR removes all deprecated code written to facilitate RCT
administration for the PingPong platform. In particular, the
`pingpong/scripts` folder contained CLI code to:
- Sync Airtable with PingPong, creating Groups, Assistants, and adding
users. These functions have been transformed into Airtable Automations
and the dedicated study website. See `pingpong/study` and `web/study`.
- Sync Airtable with Jira. These functions are no longer used.
- Create RCT exams in Qualtrics from Airtable. These functions will be
moved to a separate repository for archiving. They are no longer part of
the main focus of this repository.