Bump diff from 4.0.2 to 4.0.4 in /samples/demo (#2449)

Bumps [diff](https://github.com/kpdecker/jsdiff) from 4.0.2 to 4.0.4.
- [Changelog](https://github.com/kpdecker/jsdiff/blob/master/release-notes.md)
- [Commits](kpdecker/jsdiff@v4.0.2...v4.0.4)

---
updated-dependencies:
- dependency-name: diff
  dependency-version: 4.0.4
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]