[VersionBonding] Cap polyfill rules by explicitly picked withPhpSets() version

[TomasVotruba]

When a PHP version is picked explicitly, the SetList::PHP_POLYFILLS set is still loaded on top of the picked level sets. PhpVersionedFilter then activated any RelatedPolyfillInterface rule whose polyfill package sits in root composer.json, ignoring the picked version entirely.

So this config:

return RectorConfig::configure()
    ->withPhpSets(php82: true);

with symfony/polyfill-php83 required, still ran AddOverrideAttributeToOverriddenMethodsRector (and JsonValidateRector), producing PHP 8.3 code from a PHP 8.2 target:

 final class SomeClass extends ParentClass
 {
+    #[\Override]
     public function run()
     {
     }
 }

An explicitly picked version is an intended ceiling, so polyfilled rules above it are now skipped.

Unchanged behaviour when no version is picked — withPhpSets() resolving from composer.json keeps the full ahead-of-version polyfill activation, which is the point of the set:

// composer.json: "php": "^8.2", "symfony/polyfill-php83": "^1.0"
return RectorConfig::configure()
    ->withPhpSets();
// -> AddOverrideAttributeToOverriddenMethodsRector still active

Implementation

• withPhpSets() stores the explicitly picked version, RectorConfigBuilder::__invoke() passes it as Option::POLYFILL_CEILING_PHP_VERSION.
• PhpVersionedFilter skips the polyfill-package bypass when a ceiling is set, and gates RelatedPolyfillInterface rules on the ceiling instead of the project PHP version. The latter matters when composer.json allows a higher PHP than the picked set, e.g. "php": "^8.4" with withPhpSets(php82: true).