Bump urllib3 from 2.6.0 to 2.6.3 in /.tools/readmes

Bumps [urllib3](https://github.com/urllib3/urllib3) from 2.6.0 to 2.6.3.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@2.6.0...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>

Author: dependabot[bot]

.tools/readmes/requirements_freeze.txt

@@ -28,5 +28,5 @@ shellingham==1.5.4
 typer==0.15.1
 types-PyYAML==6.0.12.12
 typing_extensions==4.12.2
-urllib3==2.6.0
+urllib3==2.6.3
 yamale==4.0.4