Refactor codebase to eliminate calls deprecated methods of the `phpunit/phpunit`

[andrewbess]

Description (*)

There are a lot of calls deprecated methods of the phpunit/phpunit in the codebase that are deprecated in v9 and will be removed in v10.
Currently it provokes warning, but it will provoke error in future.

Method calls that should be eliminated:

• at();
• assertFileNotExists();
• assertRegExp();
• assertNotRegExp();
• setMethodsExcept();

Calls of the deprecated methods have been found in repositories described below:

• https://github.com/magento/magento2
• https://github.com/magento/partners-magento2ee
• https://github.com/magento/partners-magento2b2b
• https://github.com/magento/magento2-functional-testing-framework

AC:

• No PHPUnit warnings in console log

[m2-assistant]

Hi @andrewbess. Thank you for your report.
To help us process this issue please make sure that you provided the following information:

• Summary of the issue
• Information on your environment
• Steps to reproduce
• Expected and actual results

Please make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, please, add a comment to the issue:

@magento give me 2.4-develop instance - upcoming 2.4.x release

For more details, please, review the Magento Contributor Assistant documentation.

Please, add a comment to assign the issue: @magento I am working on this

---

• Join Magento Community Engineering Slack and ask your questions in #github channel.

⚠️ According to the Magento Contribution requirements, all issues must go through the Community Contributions Triage process. Community Contributions Triage is a public meeting.

🕙 You can find the schedule on the Magento Community Calendar page.

📞 The triage of issues happens in the queue order. If you want to speed up the delivery of your contribution, please join the Community Contributions Triage session to discuss the appropriate ticket.

🎥 You can find the recording of the previous Community Contributions Triage on the Magento Youtube Channel

✏️ Feel free to post questions/proposals/feedback related to the Community Contributions Triage process to the corresponding Slack Channel

[m2-assistant]

Hi @anzin. Thank you for working on this issue.
In order to make sure that issue has enough information and ready for development, please read and check the following instruction: 👇

• 1. Verify that issue has all the required information. (Preconditions, Steps to reproduce, Expected result, Actual result).
     Details

     If the issue has a valid description, the label Issue: Format is valid will be added to the issue automatically. Please, edit issue description if needed, until label Issue: Format is valid appears.
• 2. Verify that issue has a meaningful description and provides enough information to reproduce the issue. If the report is valid, add Issue: Clear Description label to the issue by yourself.
• 3. Add Component: XXXXX label(s) to the ticket, indicating the components it may be related to.
• 4. Verify that the issue is reproducible on 2.4-develop branch
     Details

     - Add the comment @magento give me 2.4-develop instance to deploy test instance on Magento infrastructure.
     - If the issue is reproducible on 2.4-develop branch, please, add the label Reproduced on 2.4.x.
     - If the issue is not reproducible, add your comment that issue is not reproducible and close the issue and stop verification process here!

---

• Join Magento Community Engineering Slack and ask your questions in #github channel.

[andrewbess]

There were found new warnings in inventory repo.
All warnings provided below.

1. Magento\Paypal\Controller\Billing\AgreementTest::testReturnWizardActioncreatePartialMock() called with method(s) placeBillingAgreement that do not exist in Magento\Paypal\Model\Express.
   This will not be allowed in future versions of PHPUnit.

2. Magento\CatalogInventory\Model\Quote\Item\QuantityValidatorTest::testQuoteWithOptionscreatePartialMock() called with method(s) getItem that do not exist in Magento\Framework\Event.
   This will not be allowed in future versions of PHPUnit.

3. Magento\CatalogInventory\Model\Quote\Item\QuantityValidatorTest::testQuoteWithOptionsWithErrorcreatePartialMock() called with method(s) getItem that do not exist in Magento\Framework\Event.
   createPartialMock() called with method(s) checkQtyIncrements, getMessage, getQuoteMessage, getHasError that do not exist in Magento\Framework\DataObject.
   This will not be allowed in future versions of PHPUnit.

4. Magento\CatalogInventory\Model\Quote\Item\QuantityValidatorTest::testConfigurableWithOptions with data set # 0
   createPartialMock() called with method(s) getItem that do not exist in Magento\Framework\Event.
   This will not be allowed in future versions of PHPUnit.

5. Magento\CatalogInventory\Model\Quote\Item\QuantityValidatorTest::testConfigurableWithOptions with data set # 1
   createPartialMock() called with method(s) getItem that do not exist in Magento\Framework\Event.
   This will not be allowed in future versions of PHPUnit.

6. Magento\CatalogInventory\Model\Quote\Item\QuantityValidatorTest::testConfigurableWithOptions with data set # 2
   createPartialMock() called with method(s) getItem that do not exist in Magento\Framework\Event.
   This will not be allowed in future versions of PHPUnit.

@anzin
Could you please fix it?
Thank you in advance.