Tests fail on PHP 8.4/PHPUnit 12: convert doc-comment annotations to attributes

[robin-the-going-merry]

Requested by: @Crabcyborg

Problem

Tests fail on PHP 8.4 / PHPUnit 12 with:

```
Error: Call to undefined method PHPUnit\Util\Test::parseTestMethodAnnotations()
```

`composer.json` pins `yoast/phpunit-polyfills` at `^1.0` (bumping this alone does not fix it — confirmed by testing `^4.0` locally, same error). The method isn't something phpunit-polyfills restores; it backports assertion methods, not annotation parsing.

Root cause: `PHPUnit\Util\Test::parseTestMethodAnnotations()` was removed in PHPUnit 10. It's what WP core's test scaffolding uses to read doc-comment `@ticket`/`@dataProvider`/`@group` annotations. PHPUnit 12 requires PHP 8 attributes (`#[DataProvider]`, `#[Group]`, etc.) instead of doc-comments for this metadata.

`tests/phpunit/` still uses the doc-comment style throughout — 77 files reference `@dataProvider`/`@ticket`/`@group`/`@requires` (e.g. `tests/phpunit/fields/test_FrmFieldAddress.php`, `tests/phpunit/xml/test_FrmXMLHelper.php`).

Fix

Convert the doc-comment annotations in those 77 files to PHP 8 attributes:

• `@dataProvider method_name` → `#[DataProvider('method_name')]`
• `@group name` → `#[Group('name')]`
• `@ticket` / `@requires` similarly, per PHPUnit's migration guide for doc-comment-to-attribute metadata.

Bump `yoast/phpunit-polyfills` to `^4.0` in `composer.json` alongside the conversion (needed for PHPUnit 12 compat elsewhere, but not sufficient on its own — see above).

Reference

Related PR: `#3429` (bumps CI matrix to PHP 8.5, one-line change, doesn't touch this).

[vivi-the-going-merry]

Diagnosis needs revision before this is a mechanical annotation conversion.

Verified locally (formidable-forms master, composer update yoast/phpunit-polyfills -> PHPUnit 12.5.35, PHP 8.5, real WP-core test lib): the cited error doesn't originate from this repo's own @dataProvider/@group/@ticket/@requires doc-comments. It fires in WP core's bundled tests/phpunit/includes/abstract-testcase.php's set_up() (line 143), which unconditionally calls $this->expectDeprecated() on every test, which falls to PHPUnit\Util\Test::parseTestMethodAnnotations() (line 592) - a method PHPUnit 10 removed.

Confirmed with a test carrying zero annotations of any kind (WP_Test_WordPress_Plugin_Tests::test_plugin_activated, tests/phpunit/test_wordpress_plugin_tests.php) - same fatal, same stack, before any of this repo's own 78 annotated files are even reached:

Error: Call to undefined method PHPUnit\Util\Test::parseTestMethodAnnotations()
.../wordpress-develop/tests/phpunit/includes/abstract-testcase.php:592
.../wordpress-develop/tests/phpunit/includes/abstract-testcase.php:143
.../vendor/yoast/phpunit-polyfills/src/TestCases/TestCasePHPUnitGte8.php:68
tests/phpunit/base/FrmUnitTest.php:47

Separately confirmed: converting @dataProvider/@group to #[...] attributes for tests that use them is real and necessary (PHPUnit 12 silently drops a doc-comment-only @dataProvider - 0 args passed, ArgumentCountError; dual declaration, doc-comment plus attribute together, works on both PHPUnit 9.6 and 12.5). But it doesn't unblock CI on its own - every test fatals in set_up() before its own annotations matter, since FrmUnitTest extends WP_UnitTestCase and inherits this unconditional call.

Scope is bigger than converting 78 files: either WP core's test scaffolding needs its own PHPUnit-10+ fix (out of this repo's control), or FrmUnitTest/the base test case here needs to override set_up()/expectDeprecated() to guard against the missing method - a different, larger change than what's described. Leaving unclaimed pending a scope decision.

composer.json's yoast/phpunit-polyfills bump to ^4.0 (already merged, f9151fc) is a correct, necessary piece either way.