fix: pass CODECOV_TOKEN to codecov uploader to avoid rate limit issues

[yogeshchoudhary147]

Description:
This PR updates the Unit Tests GitHub Actions workflow (.github/workflows/test.yml) for auth0-react to explicitly provide the CODECOV_TOKEN to the Codecov action.

Background:

• Previously, the Codecov uploader often failed due to hitting rate limits.
• Logs showed No token specified or token is empty, meaning the workflow wasn’t using the secret.
• Because the uploader exits with status code 0, the workflow appeared green even when coverage wasn’t uploaded.

Changes:

• Added token: ${{ secrets.CODECOV_TOKEN }} to the Upload coverage step.
• This ensures the uploader authenticates properly with Codecov and avoids rate limiting issues.

Impact:

• Coverage reports should now reliably upload in GitHub Actions for PRs and pushes to main.
• Failures due to rate limiting should no longer occur.

[developerkunal]

LGTM