Bump urllib3 from 1.26.7 to 1.26.18

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.7 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@1.26.7...1.26.18)

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

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

Author: dependabot[bot]

requirements.txt

@@ -6,5 +6,5 @@ python-baseconv == 1.2.2
 requests ==2.31.0
 six ==1.16.0
 gTTS ==2.2.3
-urllib3 ==1.26.7
+urllib3 ==1.26.18
 click ==8.0.3