Main changes:
- type checker cares about the return value (`void`) of handlers, so no
more `return res.send("...")` as that returns `express` type.
- regexes on slugs no longer supported, but we weren't really using them
in any meaningful way. The two places that had to be updated:
- `/clientstate/:clientstate64` - now uses a regex directly and tests added (thanks @partouf for spotting #4844)
- `/bits/:bits.html` - was some `\w+` but I believe that's unnecessary
for the same reasons
- actually call the Sentry handler. I don't know if this actually worked
before but the API checks suggest not.
20048616da