phpstan-doctrine Property is never written on inversed side of OneToOne relation properties

Hello, First of all thank you for all your work, it's great!

We recently upgraded to the latest phpstan/phpstan and phpstan/phpstan-doctrine and we started to have some errors reported on inversed side of OneToOne relationship properties.

For example, I have two entities:

class Signature {
  // ...

  /**
   * @ORM\OneToOne(targetEntity="App\Entity\Author", inversedBy="signature")
   * @ORM\JoinColumn(onDelete="SET NULL")
   *
   * @var Author|null
   */
  private $author;

  // ...
}

class Author {
  // ...

  /**
   * @ORM\OneToOne(targetEntity="App\Entity\Signature", mappedBy="author")
   *
   * @var Signature|null
   */
  private $signature;

  // ...
}

Both entities have a constructor and they are both non read-only entities. When I run phpstan I received the error Property App\Entity\Author::$signature is never written, only read. 💡 See: https://phpstan.org/developing-extensions/always-read-written-properties. Following the rules explained in https://phpstan.org/developing-extensions/always-read-written-properties it's correct that this error is raised but, I was wondering, if this is really a wanted behavior for this particular case. If it's not, I'd be happy to try to find a fix for it and submit a PR.

phpstan/phpstan version: 1.3.0 phpstan/phpstan-doctrine version: 1.0.2