Bump engine.io and pxt-common-packages

Bumps [engine.io](https://github.com/socketio/engine.io) to 6.2.1 and updates ancestor dependency [pxt-common-packages](https://github.com/Microsoft/pxt-common-packages). These dependencies need to be updated together.


Updates `engine.io` from 3.2.1 to 6.2.1
- [Release notes](https://github.com/socketio/engine.io/releases)
- [Changelog](https://github.com/socketio/engine.io/blob/main/CHANGELOG.md)
- [Commits](https://github.com/socketio/engine.io/compare/3.2.1...6.2.1)

Updates `pxt-common-packages` from 9.0.1 to 9.5.12
- [Release notes](https://github.com/Microsoft/pxt-common-packages/releases)
- [Commits](https://github.com/Microsoft/pxt-common-packages/compare/v9.0.1...v9.5.12)

---
updated-dependencies:
- dependency-name: engine.io
  dependency-type: indirect
- dependency-name: pxt-common-packages
  dependency-type: direct:production
...

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

package.json

@@ -45,7 +45,7 @@
         "typescript": "4.2.3"
     },
     "dependencies": {
-        "pxt-common-packages": "9.0.1",
+        "pxt-common-packages": "9.5.12",
         "pxt-core": "7.0.22"
     }
 }