Bump @grafana/ui in /plugins/grafana-custom-plugins/grafana-chord-plugin

Bumps [@grafana/ui](https://github.com/grafana/grafana/tree/HEAD/packages/grafana-ui) from 9.0.4 to 9.5.6.
- [Release notes](https://github.com/grafana/grafana/releases)
- [Changelog](https://github.com/grafana/grafana/blob/main/CHANGELOG.md)
- [Commits](https://github.com/grafana/grafana/commits/v9.5.6/packages/grafana-ui)

---
updated-dependencies:
- dependency-name: "@grafana/ui"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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