Bump urllib3 from 1.26.5 to 1.26.18

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.5 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@1.26.5...1.26.18)

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

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -13,7 +13,7 @@ requests==2.25.1
 requests-oauthlib==1.3.0
 scipy==1.6.2
 tensorflow-cpu==2.5.2
-urllib3==1.26.5
+urllib3==1.26.18
 Werkzeug==2.0.1
 gunicorn==19.8.0
 dnspython==2.1.0