<!-- Please complete the template below as best as you can. Make sure to check if this issue has already been raised by someone else first to avoid duplication. For each section below, please add screenshots or links or anything that may help visual learners understand the problem better, even if this takes you an extra minute or two this is a great help to some folks. https://www.learning-styles-online.com/style/visual-spatial/ --> ### Problem We have dead code related to the [`payment_form_url`](https://gitlab.com/gitlab-org/gitlab/-/blob/94243d5eb71f9f1f62011f544f7f87bd707b5403/ee/config/routes/directs/subscription_portal.rb#L11-13) in gitlab.com and [`cc_validation`](https://gitlab.com/gitlab-org/customers-gitlab-com/-/blob/e1abfaa0c9f5da700a5dc1bd95f00229cbf82abb/app/models/payment_form/new_credit_card.rb#L15) in customers.gitlab.com. The use of this Zuora HPM was removed here: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/167412/diffs#8671ae780923b8e431bb4fd401152fb4222b9e9c_49_0. ### Proposal Before we remove the Zuora HPMs, these should be completed: 1. https://gitlab.com/gitlab-org/customers-gitlab-com/-/issues/12406+ 1. https://gitlab.com/gitlab-org/gitlab/-/issues/524138+ After this we can delete the Zuora HPM in development, staging, staging-ref, and production. This requires a [CM request](https://gitlab.com/gitlab-com/business-technology/enterprise-apps/financeops/finance-systems/-/issues/new?issuable_template=CM%253A%2520Zuora%2520Configuration%2520Changes%2520%28%2520Fields%252CMigrations%252CCancellations%29#), like [this one](https://gitlab.com/gitlab-com/business-technology/enterprise-apps/financeops/finance-systems/-/issues/2520#note_2308427112). <!-- Consult with `@gitlab-com/business-technology/enterprise-apps/zuora-architects` on the ~"Enterprise Applications" team if Zuora business logic is involved. -->