[Rector] Skip deprecated rules in set + check bare int refactor() return

[TomasVotruba]

Two src/Rules/Rector/ improvements.

1. PhpUpgradeDowngradeRegisteredInSetRule — skip deprecated rules

The rule demands every Php*/DowngradePhp* Rector rule be registered in its matching config set:

Register "Rector\Php73\Rector\FuncCall\JsonThrowOnErrorRector" service to "php73.php" config set

Deprecated rules (marker Rector\Configuration\Deprecation\Contract\DeprecatedInterface) are on their way out and are not registered in sets, so they are now skipped — same treatment as ConfigurableRectorInterface.

use Rector\Configuration\Deprecation\Contract\DeprecatedInterface;
use Rector\Contract\Rector\RectorInterface;

// before: "Register ... to php80.php config set"   after: skipped
final class SomeDeprecatedPhp80Rector implements RectorInterface, DeprecatedInterface
{
}

2. NoIntegerRefactorReturnRule — also check bare int return type

Previously only a UnionType return type (e.g. Node|int) was inspected; a bare int return type slipped through unchecked. Now bare int is checked too, while REMOVE_NODE stays allowed.

// now reported — was silently skipped before
public function refactor(Node $node): int
{
    return NodeVisitor::DONT_TRAVERSE_CHILDREN;
}

// allowed
public function refactor(Node $node): int
{
    return NodeVisitor::REMOVE_NODE;
}