How to return a generic interface in PHP / PHPStan?

I'm using generics to type hint some classes and interfaces in php/phpstan. What i want to achieve is that a function returns a an interface object but with generic hinting:

class Car
{
}

/**
 * @template S of object
 */
interface BuilderInterface
{
    /**
     * @return S
     */
    public function build(): object;
}

/**
 * @implements BuilderInterface<Car>
 */
class CarBuilder implements BuilderInterface
{
    public function build(): object
    {
        return new Car();
    }
    
    public function notAnInterfaceFunc(): void
    {
    }
}

/**
 * @template T of BuilderInterface
 * @param class-string<T> $builderClass
 * @return T
 */
function createBuilder(string $builderClass): BuilderInterface
{   
    return new $builderClass();
}

/**
 * @template T of BuilderInterface
 * @param class-string<T> $builderClass
 * @return BuilderInterface
 */
function createBuilder1(string $builderClass): BuilderInterface
{   
    return new $builderClass();
}

$builder = createBuilder(CarBuilder::class);
\PHPStan\dumpType($builder->build()); // proper return object is of type Car
$builder->notAnInterfaceFunc(); // the function is callable


$builder1 = createBuilder1(CarBuilder::class);
\PHPStan\dumpType($builder1->build()); // return object is 'object'
$builder1->notAnInterfaceFunc(); // is not callable

Take a look at both createBuilder() functions. The second one acts like i want and returns an interface of CarBuilder::class, but it's doesn't properly sets the generic type for the CarBuilder class.

What i want:

• $builder->build() returns an object of type Car
• notAnInterfaceFunc() is not callbable

I've made a phpstan pastebin, so you can play around with the code: https://phpstan.org/r/3fa3c78c-fff1-4590-8778-51e7475c470a.