Fixed ability to save configuration in field without label

[AndreyChorniy]

Description (*)

This PR add the ability to save the configuration in the field without a label.

Fixed Issues (if relevant)

1. system.xml file validation issue #23899: system.xml file validation issue

Manual testing scenarios (*)

1. In system.xml create field without a label:

`<group id="test_group" translate="label" type="text" sortOrder="90" showInDefault="1" showInWebsite="1" showInStore="1">
                <field id="test_field" translate="label comment" type="text" sortOrder="10" showInDefault="1" showInWebsite="0" showInStore="0" canRestore="1">
                    <comment>Use {{name}} as Product Name placeholder</comment>
                </field>
</group>`

2. Go to admin panel System -> Configuration -> {path_to_your_new_field}
3. Fill this field
4. Save configuration

Questions or comments

This fix deletes part of if expression. In my opinion, we don't need to disallow save fields without labels.

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds are green)

[m2-assistant]

Hi @AndreyChorniy. Thank you for your contribution
Here is some useful tips how you can test your changes using Magento test environment.
Add the comment under your pull request to deploy test or vanilla Magento instance:

• @magento give me test instance - deploy test instance based on PR changes
• @magento give me 2.4-develop instance - deploy vanilla Magento instance

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

[magento-engcom-team]

Hi @aleron75, thank you for the review.
ENGCOM-6460 has been created to process this Pull Request
✳️ @aleron75, could you please add one of the following labels to the Pull Request?

Label	Description
Auto-Tests: Covered	All changes in Pull Request is covered by auto-tests
Auto-Tests: Not Covered	Changes in Pull Request requires coverage by auto-tests
Auto-Tests: Not Required	Changes in Pull Request does not require coverage by auto-tests

[engcom-Charlie]

Hello @AndreyChorniy
Due to Magento Definition of Done all code must be covered by tests. Please cover your fix by automated tests.
Thanks!

[engcom-Golf]

I will take care of test coverage

[engcom-Golf]

Hi @aleron75 all changes covered by unit test could you please review ?

[aleron75]

Hello @AndreyChorniy, can you please check the failing unit test?
Thanks

[engcom-Golf]

@aleron75 test failed because i changed mock file, will fix them tomorrow's, and static test.

[engcom-Golf]

@aleron75 all done ✔️

[magento-engcom-team]

Hi @aleron75, thank you for the review.
ENGCOM-6460 has been created to process this Pull Request

[engcom-Delta]

✔️ QA passed

[m2-assistant]

Hi @AndreyChorniy, thank you for your contribution!
Please, complete Contribution Survey, it will take less than a minute.
Your feedback will help us to improve contribution process.