maintenance: fix docusaurus-tests.yml workflow configuration

## Summary

Fix the broken configuration in `.github/workflows/docusaurus-tests.yml`.

Broken out from parent issue #2214.

## Changes

- Correct the `docusaurus-tests.yml` workflow configuration so the workflow parses as valid YAML and runs as intended.

## Acceptance Criteria

- [ ] `docusaurus-tests.yml` parses as valid YAML.
- [ ] The docusaurus tests workflow executes successfully in CI.
Related to #2214

> Generated by [Issue Triage](https://github.com/microsoft/hve-core/actions/runs/28314978133) for issue #2214 · 79.7 AIC · ⌖ 13.1 AIC · ⊞ 28.5K · [◷](https://github.com/search?q=repo%3Amicrosoft%2Fhve-core+is%3Aissue+%22gh-aw-workflow-call-id%3A+microsoft%2Fhve-core%2Fissue-triage%22&type=issues)

Open .github/workflows/docusaurus-tests.yml and inspect the workflow configuration first. Validate that the file parses as YAML, then use the workflow’s CI run to confirm the Docusaurus tests execute successfully. Done means the configuration is valid and the workflow completes successfully.

Written by the indexing model from the issue text.