Bump pip from 20.3.3 to 21.0.1 in /python/helpers

Bumps [pip](https://github.com/pypa/pip) from 20.3.3 to 21.0.1.
- [Release notes](https://github.com/pypa/pip/releases)
- [Changelog](https://github.com/pypa/pip/blob/master/NEWS.rst)
- [Commits](pypa/pip@20.3.3...21.0.1)

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

python/helpers/requirements.txt

@@ -1,4 +1,4 @@
-pip==20.3.3
+pip==21.0.1
 pip-tools==5.5.0
 flake8==3.8.4
 hashin==0.15.0