Bump http-cache-semantics and npm in /assets

Removes [http-cache-semantics](https://github.com/kornelski/http-cache-semantics). It's no longer used after updating ancestor dependency [npm](https://github.com/npm/cli). These dependencies need to be updated together.


Removes `http-cache-semantics`

Updates `npm` from 6.14.5 to 9.4.1
- [Release notes](https://github.com/npm/cli/releases)
- [Changelog](https://github.com/npm/cli/blob/latest/CHANGELOG.md)
- [Commits](npm/cli@v6.14.5...v9.4.1)

---
updated-dependencies:
- dependency-name: http-cache-semantics
  dependency-type: indirect
- dependency-name: npm
  dependency-type: direct:development
...

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

Author: dependabot[bot]