build(deps): bump ujson from 4.0.2 to 5.4.0 in /docs (#6)

Bumps [ujson](https://github.com/ultrajson/ultrajson) from 4.0.2 to 5.4.0.
- [Release notes](https://github.com/ultrajson/ultrajson/releases)
- [Commits](ultrajson/ultrajson@4.0.2...5.4.0)

---
updated-dependencies:
- dependency-name: ujson
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

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

docs/requirements.txt

@@ -28,6 +28,6 @@ six==1.16.0
 toml==0.10.2
 tornado==6.1
 tqdm==4.60.0
-ujson==4.0.2
+ujson==5.4.0
 urllib3==1.26.5
 wcwidth==0.2.5