chore(deps): bump tmp and @expo/devcert in /examples/rn-expo

Removes [tmp](https://github.com/raszi/node-tmp). It's no longer used after updating ancestor dependency [@expo/devcert](https://github.com/expo/devcert). These dependencies need to be updated together.


Removes `tmp`

Updates `@expo/devcert` from 1.1.2 to 1.2.0
- [Changelog](https://github.com/expo/devcert/blob/master/CHANGELOG.md)
- [Commits](expo/devcert@v1.1.2...v1.2.0)

---
updated-dependencies:
- dependency-name: tmp
  dependency-version: 
  dependency-type: indirect
- dependency-name: "@expo/devcert"
  dependency-version: 1.2.0
  dependency-type: indirect
...

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

Author: dependabot[bot]