Bump urllib3 from 1.26.8 to 1.26.18

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.8 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@1.26.8...1.26.18)

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

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

requirements.txt

@@ -33,4 +33,4 @@ six==1.16.0
 tifffile==2022.2.9
 tomli==2.0.1
 tqdm==4.62.3
-urllib3==1.26.8
+urllib3==1.26.18