Remove legacy checkout checkbox from settings page

[malithsen]

Fixes STRIPE-535

Changes proposed in this Pull Request:

• Remove the UI checkbox to enable Legacy Checkout.
• Remove Legacy Checkout e2e tests as there's no way to setup tests without the checkbox.

Not removed:

• Tracks events
• System report labels
• References to legacy checkout throughout the codebase.

We'd want to keep them until we remove the filter introduced in #4385

Testing instructions

1. Go to Stripe settings YOUR_TEST_SITE/wp-admin/admin.php?page=wc-settings&tab=checkout&section=stripe&panel=settings.
2. Make sure the checkbox to enable Legacy Checkout is not visible.
3. (Optional exploratory test) Make sure there's no other option in the UI to enable Legacy checkout

---

• Covered with tests (or have a good reason not to test in description ☝️)
• Tested on mobile (or does not apply)

Changelog entry

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Changelog Entry Comment

Comment

Post merge

• Added testing instructions to the Release Testing Instructions wiki page (or does not apply)
• Added the needs docs label (or does not apply)
• Included this PR in the Release Thread scope (or does not apply)

[Mayisha]

Let's remove this from the update function also. Removing only from the update function is sufficient as we still want the value in GET response.

[malithsen]

Let's remove this from the update function also. Removing only from the update function is sufficient as we still want the value in GET response

@Mayisha Thanks, that makes sense. Updated in 3915e76

[Mayisha]

Looks good to me 👍

✅ Legacy checkout checkbox is not displayed anymore on the settings page.
✅ Updating and saving the settings works without any errors.

[annemirasol]

Let's remove this from the update function also. Removing only from the update function is sufficient as we still want the value in GET response

@Mayisha Thanks, that makes sense. Updated in 3915e76

Should we also remove the method update_is_upe_enabled itself? It is private and no longer being used anywhere else.

[malithsen]

Should we also remove the method update_is_upe_enabled itself? It is private and no longer being used anywhere else.

@annemirasol Agreed. Removed in dd7bb07

[github-actions]

📈 PHP Unit Code Coverage Report

Package	Line Rate	Health
includes/admin/class-wc-rest-stripe-settings-controller.php	82%	✔
Summary	44% (7163 / 16355)	❌

[annemirasol]

No regressions observed, LGTM!