Fix ObjectStorage template in stub

We have to use `TEntity of object` instead of
`TEntity`.

Author: sascha-egerer

stubs/ObjectStorage.stub

@@ -2,7 +2,7 @@
 namespace TYPO3\CMS\Extbase\Persistence;
 
 /**
- * @template TEntity
+ * @template TEntity of object
  * @implements \ArrayAccess<string, TEntity>
  * @implements \Iterator<string, TEntity>
  * @phpstan-type ObjectStorageInternal array{obj: TEntity, inf: mixed}

tests/Unit/Type/data/object-storage-stub-files.php

@@ -29,6 +29,7 @@ public function foo(): void
 		}
 
 		assertType(self::class . '|null', $objectStorage->offsetGet(0));
+		assertType(self::class . '|null', $objectStorage->current());
 
 		// We ignore errors in the next line as this will produce an
 		// "Offset 0 does not exist on TYPO3\CMS\Extbase\Persistence\ObjectStorage<ObjectStorage\My\Test\Extension\Domain\Model\MyModel>