Bump express and umi in /app

Removes [express](https://github.com/expressjs/express). It's no longer used after updating ancestor dependency [umi](https://github.com/umijs/umi). These dependencies need to be updated together.


Removes `express`

Updates `umi` from 3.2.7 to 3.5.35
- [Release notes](https://github.com/umijs/umi/releases)
- [Commits](umijs/umi@v3.2.7...v3.5.35)

---
updated-dependencies:
- dependency-name: express
  dependency-type: indirect
- dependency-name: umi
  dependency-type: direct:development
...

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