Bump jinja2 from 2.11.2 to 2.11.3 in /sample-apps/flask (#278)

Bumps [jinja2](https://github.com/pallets/jinja) from 2.11.2 to 2.11.3.
- [Release notes](https://github.com/pallets/jinja/releases)
- [Changelog](https://github.com/pallets/jinja/blob/master/CHANGES.rst)
- [Commits](pallets/jinja@2.11.2...2.11.3)

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

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

Author: dependabot[bot]

sample-apps/flask/requirements.txt

@@ -5,7 +5,7 @@ click==7.1.2
 Flask==1.1.2
 idna==2.9
 itsdangerous==1.1.0
-Jinja2==2.11.2
+Jinja2==2.11.3
 MarkupSafe==1.1.1
 requests==2.23.0
 urllib3==1.25.9