Bump @fluentui/react from 8.112.5 to 8.120.5 in /app/frontend

Bumps [@fluentui/react](https://github.com/microsoft/fluentui) from 8.112.5 to 8.120.5.
- [Release notes](https://github.com/microsoft/fluentui/releases)
- [Changelog](https://github.com/microsoft/fluentui/blob/master/azure-pipelines.release-fluentui.yml)
- [Commits](https://github.com/microsoft/fluentui/compare/@fluentui/react_v8.112.5...@fluentui/react_v8.120.5)

---
updated-dependencies:
- dependency-name: "@fluentui/react"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]