PHPStan: Negated boolean expression is always false in all action plugins

Problem/Motivation

The following code is not exactly doing what it appears to do, at least with later and stricter PHP versions:

      /** @var \Drupal\mautic_api\Entity\MauticApiConnection $connection */
      $connection = $this->entityTypeManager
        ->getStorage('mautic_api_connection')
        ->load($connectionId);

      if (!$connection) {
        $this->logger->error('Mautic connection with ID @id not found', [
          '@id' => $connectionId,
        ]);
        return;
      }

According to the PHPDoc, $connection is always an object and NULL.

Proposed resolution

The PHPDoc needs to be updated to this:

      /** @var \Drupal\mautic_api\Entity\MauticApiConnection|null $connection */

This indicates that $connection can either be an object or NULL.

PHPStan level 6 finds similar issues in all action plugins.