Bump urllib3 from 2.2.3 to 2.6.3 in /example

Bumps [urllib3](https://github.com/urllib3/urllib3) from 2.2.3 to 2.6.3.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](https://github.com/urllib3/urllib3/compare/2.2.3...2.6.3)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-version: 2.6.3
  dependency-type: direct:production
...

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

example/requirements.txt

@@ -14,5 +14,5 @@ rfc3987==1.3.8
 signposting==0.9.9
 soupsieve==2.6
 sqlparse==0.5.1
-urllib3==2.2.3
+urllib3==2.6.3
 rocrate==0.11.0