chore: Bump some devdeps

[rschristian]

Bumps some deps to (hopefully) fix the CI issues:

• chai & sinon-chai
  • Fixing conflicting peer deps
• preact
  • Necessary to incorporate in SignalLike (see #452)
• typescript
  • Necessary to support newer lib features that Preact ships (matched version to preact repo)
• copyfiles, mkdirp, rimraf, npm-merge-driver-install
  • Seem to all be legacy & unused