[Configuration] Load single composer-based PHPUnit set in withComposerBased()

[TomasVotruba]

withComposerBased(phpunit: true) went through the set group machinery: SetGroup::PHPUNIT -> SetProviderCollector -> SetManager::matchBySetGroups() -> installed package resolving -> every matching phpunit40.php ... phpunit130.php set plus composer-based.php.

The composer-based.php set already binds each rule and rule configuration to the installed phpunit/phpunit version on its own, via ComposerPackageConstraintInterface and ruleWithConfigurationComposerVersionBound(). So the group lookup and the per-version sets are not needed - a single set include is enough.

 $setMap = [
     SetGroup::TWIG => $twig,
     SetGroup::DOCTRINE => $doctrine,
-    SetGroup::PHPUNIT => $phpunit,
     SetGroup::SYMFONY => $symfony,
     ...
 ];

+if ($phpunit) {
+    $this->sets[] = PHPUnitSetList::COMPOSER_BASED;
+}

Behavior for the user stays the same:

return RectorConfig::configure()
    ->withComposerBased(phpunit: true);

 final class SomeTest extends TestCase
 {
-    /**
-     * @dataProvider provideData
-     */
+    #[\PHPUnit\Framework\Attributes\DataProvider('provideData')]
     public function test(): void
     {
     }
 }