Update pyxform version to 2.1.0

[RuthShryock]

Checklist

1. If you've added code that should be tested, add tests
2. If you've changed APIs, update (or create!) the documentation
3. Ensure the tests pass
4. Make sure that your code lints and that you've followed our coding style
5. Write a title and, if necessary, a description of your work suitable for publishing in our release notes
6. Mention any related issues in this repository (as #ISSUE) and in other repositories (as kobotoolbox/other#ISSUE)
7. Open an issue in the docs if there are UI/UX changes

Notes

Update pyxfrom to the latest release version 2.1.0 since form pack also uses the latest release.

This update is deployed to kf.du.kbtdev.org for testing.

[notion-workspace]

Update pyxform in kpi and formpack