chore(deps): bump @radix-ui/react-dropdown-menu in /ui

Bumps [@radix-ui/react-dropdown-menu](https://github.com/radix-ui/primitives) from 2.1.5 to 2.1.6.
- [Changelog](https://github.com/radix-ui/primitives/blob/main/release-process.md)
- [Commits](https://github.com/radix-ui/primitives/commits)

---
updated-dependencies:
- dependency-name: "@radix-ui/react-dropdown-menu"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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