fix PHPStan

[AurelDemiri]

Fixes: using nullsafe property access on non-nullable type

[what-the-diff]

PR Summary 🪄

• Adios Null Coalescing Operator! 🎉
  We're saying goodbye to using the null coalescing operator (this weird symbol ?->) within our code! Why is that important? Well, it's all about how we access and interact with the properties in our objects. Previously, we used this symbol as a sort of safety measure to prevent any errors if something doesn't happen to be there (we call this a null value). But now, we've grown more confident and are boldly accessing object properties directly. This change can actually help make our code cleaner and more straight forward. Get ready to find $this->theme->value; in place of the old return $this->theme?->value; line! 🥳