Fix MorphTo Model Doc Generation (#1668)

fix:
```php
    /**
     * @return MorphTo<contravariant ModelA|ModelB, $this>
     */
    public function reminderable(): MorphTo {
        return $this->morphTo(__FUNCTION__, 'entity', 'entity_id');
    }
```
From:
```php
* @property-read contravariant ModelA|ModelB $reminderable
 ```
To:
```php
* @property-read ModelA|ModelB $reminderable
 ```
Fixes: #1667

src/Console/ModelsCommand.php

@@ -826,7 +826,7 @@ class ModelsCommand extends Command
                                     $matches = [];
                                     $returnType = $this->getReturnTypeFromDocBlock($reflection);
                                     if ($returnType !== null) {
-                                        preg_match('/MorphTo<(.+?)(?:,|>)/i', $returnType, $matches);
+                                        preg_match('/MorphTo<(?:contravariant\s+)?(.+?)(?:,|>)/i', $returnType, $matches);
                                     }
 
                                     // Model isn't specified because relation is polymorphic