Remove paymentsOnboardingInPointOfSale feature flag a few weeks after release

[jaclync]

Closes: #14343

Description

The POS payments onboarding feature was released in 21.2 on December 9. Now that it's been a few weeks, it's ready to remove the paymentsOnboardingInPointOfSale feature flag and its associated logic from various parts of the codebase.

Removal of paymentsOnboardingInPointOfSale feature flag:

• Experiments/Experiments/DefaultFeatureFlagService.swift: Removed the paymentsOnboardingInPointOfSale case from the feature flag service.
• Experiments/Experiments/FeatureFlag.swift: Removed the paymentsOnboardingInPointOfSale enum case.

Updates to eligibility checker logic:

• WooCommerce/Classes/ViewRelated/Dashboard/Settings/POS/POSEligibilityChecker.swift: Removed checks and logic related to the paymentsOnboardingInPointOfSale feature flag. [1] [2]

Updates to mock feature flag service:

• WooCommerce/WooCommerceTests/Mocks/MockFeatureFlagService.swift: Removed the paymentsOnboardingInPointOfSale property and related logic. [1] [2] [3] [4]

Updates to unit tests:

• WooCommerce/WooCommerceTests/ViewRelated/Settings/POS/POSEligibilityCheckerTests.swift: Removed tests related to the paymentsOnboardingInPointOfSale feature flag and updated existing tests accordingly. [1] [2] [3] [4]

Steps to reproduce

Optional - feel free to do a confidence test on the payments onboarding by making sure POS is eligible for a store with incomplete payments onboarding state.

Testing information

• @jaclync smoke tests POS before merging

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• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

Reviewer (or Author, in the case of optional code reviews):

Please make sure these conditions are met before approving the PR, or request changes if the PR needs improvement:

• The PR is small and has a clear, single focus, or a valid explanation is provided in the description. If needed, please request to split it into smaller PRs.
• Ensure Adequate Unit Test Coverage: The changes are reasonably covered by unit tests or an explanation is provided in the PR description.
• Manual Testing: The author listed all the tests they ran, including smoke tests when needed (e.g., for refactorings). The reviewer confirmed that the PR works as expected on all devices (phone/tablet) and no regressions are added.

[wpmobilebot]

📲 You can test the changes from this Pull Request in WooCommerce iOS by scanning the QR code below to install the corresponding build.

	App Name	WooCommerce iOS
	Build Number	pr14787-a7abd66
	Version	21.3
	Bundle ID	com.automattic.alpha.woocommerce
	Commit	a7abd66
	App Center Build	WooCommerce - Prototype Builds #12348

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[staskus]

cardPresentPaymentsOnboarding could be removed from the class.

[jaclync]

Great catch! Removed all related onboarding logic in POS eligibility check in a7abd66.