Bump urllib3 from 1.26.3 to 1.26.4 (#306)

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.3 to 1.26.4.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.26.3...1.26.4)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements_frozen.txt

@@ -37,5 +37,5 @@ six==1.15.0
 snaptime==0.2.4
 toml==0.10.2
 tzlocal==2.1
-urllib3==1.26.3
+urllib3==1.26.4
 wrapt==1.11.1