build(deps-dev): bump @microsoft/api-documenter from 7.21.3 to 7.21.5 (…

…#1076)

Bumps [@microsoft/api-documenter](https://github.com/microsoft/rushstack/tree/HEAD/apps/api-documenter) from 7.21.3 to 7.21.5.
- [Release notes](https://github.com/microsoft/rushstack/releases)
- [Changelog](https://github.com/microsoft/rushstack/blob/main/apps/api-documenter/CHANGELOG.md)
- [Commits](https://github.com/microsoft/rushstack/commits/@microsoft/api-documenter_v7.21.5/apps/api-documenter)

---
updated-dependencies:
- dependency-name: "@microsoft/api-documenter"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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