Pull request checks are failing after release of WordPress 6.1

[aprea]

Describe the bug

The following pull request checks started failing shortly after the release of WordPress 6.1.

• Compatibility - WC, WP and PHP
• Code coverage
• PHP linting and tests

Example errors:

1) WC_REST_Payments_Settings_Controller_Test::test_get_settings_request_returns_status_code_200
Undefined property: WC_REST_Payments_Settings_Controller_Test::$mock_token_service

/home/runner/work/woocommerce-payments/woocommerce-payments/tests/unit/admin/test-class-wc-rest-payments-settings-controller.php:131
/home/runner/work/woocommerce-payments/woocommerce-payments/vendor/yoast/phpunit-polyfills/src/TestCases/TestCasePHPUnitGte8.php:56

2) WC_REST_Payments_Settings_Controller_Test::test_get_settings_returns_enabled_payment_method_ids
Undefined property: WC_REST_Payments_Settings_Controller_Test::$mock_token_service

/home/runner/work/woocommerce-payments/woocommerce-payments/tests/unit/admin/test-class-wc-rest-payments-settings-controller.php:131
/home/runner/work/woocommerce-payments/woocommerce-payments/vendor/yoast/phpunit-polyfills/src/TestCases/TestCasePHPUnitGte8.php:56

3) WC_REST_Payments_Settings_Controller_Test::test_get_settings_returns_available_payment_method_ids
Undefined property: WC_REST_Payments_Settings_Controller_Test::$mock_token_service

Example test failures:

1) WC_Payments_Webhook_Processing_Service_Test::test_payment_intent_successful_and_completes_order
Unexpected incorrect usage notice for WP_Object_Cache::delete.
Cache key must be integer or non-empty string, NULL given. (This message was added in version 6.1.0.)
Failed asserting that an array is empty.

/tmp/wordpress-tests-lib/includes/abstract-testcase.php:615
/tmp/wordpress-tests-lib/includes/abstract-testcase.php:627
/home/runner/work/woocommerce-payments/woocommerce-payments/vendor/yoast/phpunit-polyfills/src/TestCases/TestCasePHPUnitGte8.php:80

2) WC_Payments_Webhook_Processing_Service_Test::test_payment_intent_successful_and_completes_order_without_intent_id
Unexpected incorrect usage notice for WP_Object_Cache::delete.
Cache key must be integer or non-empty string, NULL given. (This message was added in version 6.1.0.)
Failed asserting that an array is empty.

/tmp/wordpress-tests-lib/includes/abstract-testcase.php:615
/tmp/wordpress-tests-lib/includes/abstract-testcase.php:627
/home/runner/work/woocommerce-payments/woocommerce-payments/vendor/yoast/phpunit-polyfills/src/TestCases/TestCasePHPUnitGte8.php:80

3) WC_Payments_Webhook_Processing_Service_Test::test_payment_intent_successful_when_retrying
Unexpected incorrect usage notice for WP_Object_Cache::delete.
Cache key must be integer or non-empty string, NULL given. (This message was added in version 6.1.0.)
Failed asserting that an array is empty.

/tmp/wordpress-tests-lib/includes/abstract-testcase.php:615
/tmp/wordpress-tests-lib/includes/abstract-testcase.php:627
/home/runner/work/woocommerce-payments/woocommerce-payments/vendor/yoast/phpunit-polyfills/src/TestCases/TestCasePHPUnitGte8.php:80

To Reproduce

1. Branch off develop.
2. Commit some code.
3. Push your changes.
4. Create a pull request.
5. Observe the compatibility, code coverage and PHP linting and tests pull request checks fail.

Actual behavior

Pull request checks fail when testing against WordPress 6.1.

Screenshots

Expected behavior

Pull request checks pass as expected when testing against WordPress 6.1.

Additional context

Discussed in Slack here p1667353741152329-slack-CGGCLBN58