Bump koa and @vscode/test-web (#289)

Bumps [koa](https://github.com/koajs/koa) to 3.0.1 and updates ancestor dependency [@vscode/test-web](https://github.com/microsoft/vscode-test-web). These dependencies need to be updated together.


Updates `koa` from 2.16.1 to 3.0.1
- [Release notes](https://github.com/koajs/koa/releases)
- [Changelog](https://github.com/koajs/koa/blob/master/History.md)
- [Commits](koajs/koa@v2.16.1...v3.0.1)

Updates `@vscode/test-web` from 0.0.67 to 0.0.71
- [Release notes](https://github.com/microsoft/vscode-test-web/releases)
- [Changelog](https://github.com/microsoft/vscode-test-web/blob/main/CHANGELOG.md)
- [Commits](microsoft/vscode-test-web@v0.0.67...v0.0.71)

---
updated-dependencies:
- dependency-name: koa
  dependency-version: 3.0.1
  dependency-type: indirect
- dependency-name: "@vscode/test-web"
  dependency-version: 0.0.71
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]