build(deps): update urllib3 requirement from >=2.2.2 to >=2.6.3

Updates the requirements on [urllib3](https://github.com/urllib3/urllib3) to permit the latest version.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@2.2.2...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]

requirements.txt

@@ -1,3 +1,3 @@
 requests
-urllib3>=2.2.2 # not directly required, pinned by Snyk to avoid a vulnerability
+urllib3>=2.6.3 # not directly required, pinned by Snyk to avoid a vulnerability
 zombie-imp

test-requirements.txt

@@ -9,5 +9,5 @@ PyYAML
 requests
 setuptools>=70.0.0
 tox
-urllib3>=2.2.2 # not directly required, pinned by Snyk to avoid a vulnerability
+urllib3>=2.6.3 # not directly required, pinned by Snyk to avoid a vulnerability
 zipp>=3.19.1 # not directly required, pinned by Snyk to avoid a vulnerability