Bump urllib3 from 1.26.12 to 1.26.13 in /demo/graphtutorial

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.12 to 1.26.13.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.26.12...1.26.13)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

demo/graphtutorial/requirements.txt

@@ -14,4 +14,4 @@ PyJWT==2.6.0
 requests==2.28.1
 six==1.16.0
 typing_extensions==4.4.0
-urllib3==1.26.12
+urllib3==1.26.13