*Description:* This adds a new `replace_sensitive_sso_username` flag on the `EnterpriseCustomer` model, allowing us to configure whether or not to replace sensitive SSO usernames per-customer.
*Merge deadline:* This sprint.
*Installation instructions:* This is only useful for https://github.com/edx/edx-platform/pull/17910, so install this branch when using that PR.
[ ] Check that the versions of the requirements in the `platform-master.in` file match edx-platform.
[ ] New requirements are in the right place (`base.in` if only used in enterprise; in the correct `platform-****.in` files if they're hosted in edx-platform)
[ ] Regenerate requirements with `make upgrade && make requirements` (and make sure to fix any errors).
*DO NOT* just add dependencies to `requirements/*.txt` files.
[ ] Called `make static` for webpack bundling if any static content was updated.
[ ] All reviewers approved
[ ] CI build is green
[ ] Version bumped
[ ] Changelog record added
[ ] Documentation updated (not only docstrings)
[ ] Commits are (reasonably) squashed
[ ] Translations are updated
[ ] PR author is listed in AUTHORS
[ ] Create a tag
[ ] Check new version is pushed to PyPi after tag-triggered build is finished.
[ ] Delete working branch (if not needed anymore)
[ ] edx-platform PR (be sure to include edx-platform requirements upgrades that were present in this PR)