Convert test annotations to attributes in core's Unit tests

Problem/Motivation

Replace annotation-based test metadata with PHP attributes.

Please DO NOT change the MR here manually. The patch is automatically generated by the MR at 📌 [meta] Define a Rector rule to convert test annotations to attributes Active .

Proposed resolution

In this issue, convert core's unit tests, with the exception of:

• core/tests/Drupal/Tests/Core/Config/TypeResolverTest.php.php
• tbd

that require manual conversion in a follow up.

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet