Bump @typespec/rest from 0.72.1 to 0.73.0 in /additions

Bumps [@typespec/rest](https://github.com/microsoft/typespec) from 0.72.1 to 0.73.0.
- [Release notes](https://github.com/microsoft/typespec/releases)
- [Commits](https://github.com/microsoft/typespec/commits/@typespec/[email protected])

---
updated-dependencies:
- dependency-name: "@typespec/rest"
  dependency-version: 0.73.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]