chore(deps): bump urllib3 from 1.26.14 to 1.26.18 in /test

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.14 to 1.26.18.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.26.14...1.26.18)

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

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

test/upstream-requirements-py311.txt

@@ -33,6 +33,6 @@ six==1.16.0
 sortedcontainers==2.4.0
 toml==0.10.2
 types-toml==0.10.8.5
-urllib3==1.26.14
+urllib3==1.26.18
 Werkzeug==2.2.3
 xmltodict==0.13.0

test/upstream-requirements-py37.txt

@@ -37,7 +37,7 @@ toml==0.10.2
 tomli==2.0.1
 types-toml==0.10.8.5
 typing_extensions==4.5.0
-urllib3==1.26.14
+urllib3==1.26.18
 Werkzeug==2.2.3
 xmltodict==0.13.0
 zipp==3.14.0