chore(deps): bump postcss and @quasar/app in /editor

Bumps [postcss](https://github.com/postcss/postcss) to 8.4.31 and updates ancestor dependency [@quasar/app](https://github.com/quasarframework/quasar). These dependencies need to be updated together.


Updates `postcss` from 6.0.23 to 8.4.31
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@6.0.23...8.4.31)

Updates `@quasar/app` from 2.0.8 to 3.3.3
- [Release notes](https://github.com/quasarframework/quasar/releases)
- [Commits](https://github.com/quasarframework/quasar/compare/@quasar/app-v2.0.8...@quasar/app-v3.3.3)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: indirect
- dependency-name: "@quasar/app"
  dependency-type: direct:development
...

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