Bump urllib3 from 1.26.9 to 1.26.18 in /src

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.9 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@1.26.9...1.26.18)

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

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

src/requirements.txt

@@ -61,7 +61,7 @@ sphinxext-opengraph==0.6.3
 tabulate==0.9.0
 tornado==6.3.2
 tqdm==4.64.0
-urllib3==1.26.9
+urllib3==1.26.18
 watchdog==2.1.7
 webencodings==0.5.1
 zipp==3.8.0