Update dependency six to v1.17.0 (#462)

Author: slack-oss-bot

.github/workflows/mkdocs-requirements.txt

@@ -14,6 +14,6 @@ pymdown-extensions==10.12
 python-dateutil==2.9.0.post0
 PyYAML==6.0.2
 repackage==0.7.3
-six==1.16.0
+six==1.17.0
 termcolor==2.5.0
 tornado==6.4.1