Bump urllib3 from 1.25.6 to 1.25.8 (#106)

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.25.6 to 1.25.8.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.25.6...1.25.8)

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

Author: dependabot[bot]

requirements.txt

@@ -43,4 +43,4 @@ sphinxcontrib-jsmath==1.0.1
 sphinxcontrib-qthelp==1.0.2
 sphinxcontrib-serializinghtml==1.1.3
 tornado==6.0.3
-urllib3==1.25.6
+urllib3==1.25.8