build(deps): bump debug and express

Bumps [debug](https://github.com/debug-js/debug) and [express](https://github.com/expressjs/express). These dependencies needed to be updated together.

Updates `debug` from 0.8.1 to 4.3.4
- [Release notes](https://github.com/debug-js/debug/releases)
- [Commits](debug-js/debug@0.8.1...4.3.4)

Updates `express` from 3.4.8 to 4.18.1
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/master/History.md)
- [Commits](expressjs/express@3.4.8...4.18.1)

---
updated-dependencies:
- dependency-name: debug
  dependency-type: indirect
- dependency-name: express
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>