build(deps): bump pip-tools from 6.3.1 to 6.4.0 in /python/helpers

Bumps [pip-tools](https://github.com/jazzband/pip-tools) from 6.3.1 to 6.4.0.
- [Release notes](https://github.com/jazzband/pip-tools/releases)
- [Changelog](https://github.com/jazzband/pip-tools/blob/master/CHANGELOG.md)
- [Commits](jazzband/pip-tools@6.3.1...6.4.0)

---
updated-dependencies:
- dependency-name: pip-tools
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

python/helpers/requirements.txt

@@ -1,5 +1,5 @@
 pip==21.2.4
-pip-tools==6.3.1
+pip-tools==6.4.0
 flake8==4.0.0
 hashin==0.15.0
 pipenv==2021.5.29