Bump urllib3 from 1.26.19 to 2.5.0 in /sample-apps/flask

---
updated-dependencies:
- dependency-name: urllib3
  dependency-version: 2.5.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

sample-apps/flask/requirements.txt

@@ -4,7 +4,7 @@ chardet==5.2.0
 Flask==2.3.3
 idna==3.7
 requests==2.32.0
-urllib3==1.26.19
+urllib3==2.5.0
 Werkzeug==3.0.6
 flask-sqlalchemy==2.5.1
 SQLAlchemy==1.4