Bump socket.io-parser and karma

Bumps [socket.io-parser](https://github.com/Automattic/socket.io-parser) to 4.2.4 and updates ancestor dependency [karma](https://github.com/karma-runner/karma). These dependencies need to be updated together.


Updates `socket.io-parser` from 2.3.1 to 4.2.4
- [Release notes](https://github.com/Automattic/socket.io-parser/releases)
- [Changelog](https://github.com/socketio/socket.io-parser/blob/4.2.4/CHANGELOG.md)
- [Commits](socketio/socket.io-parser@2.3.1...4.2.4)

Updates `karma` from 1.7.1 to 6.4.3
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](karma-runner/karma@1.7.1...v6.4.3)

---
updated-dependencies:
- dependency-name: socket.io-parser
  dependency-type: indirect
- dependency-name: karma
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>