Conflicts:
- `app/javascript/packs/admin.jsx`:
This file was split between `app/javascript/core/admin.js`,
`app/javascript/pack/admin.jsx`, and
`app/javascript/flavours/glitch/packs/admin.jsx`.
Ported upstream's change, splitting the new file to
`app/javascript/core/admin.ts`, `app/javascript/packs/admin.tsx`,
and `app/javascript/flavours/glitch/packs/admin.tsx`