Bump ujson from 5.2.0 to 5.4.0 in /frameworks/Python/flask

Bumps [ujson](https://github.com/ultrajson/ultrajson) from 5.2.0 to 5.4.0.
- [Release notes](https://github.com/ultrajson/ultrajson/releases)
- [Commits](https://github.com/ultrajson/ultrajson/compare/5.2.0...5.4.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

frameworks/Python/flask/requirements-pypy.txt

@@ -11,4 +11,4 @@ MarkupSafe==2.0.1
 meinheld==1.0.2
 uWSGI==2.0.19.1
 Werkzeug==2.0.1
-ujson==5.2.0
+ujson==5.4.0

frameworks/Python/flask/requirements.txt

@@ -12,5 +12,5 @@ MarkupSafe==2.0.1
 meinheld==1.0.2
 uWSGI==2.0.19.1
 Werkzeug==2.0.1
-ujson==5.2.0
+ujson==5.4.0
 orjson==3.6.0