Merge branch '7.4' into 8.0

* 7.4:
  Minor tweaks
  [ObjectMapper] embed collection transformer

Author: javiereguiluz

object_mapper.rst

@@ -424,6 +424,33 @@ And the related target object must define the ``createFromLegacy()`` method::
         }
     }
 
+Mapping Collections
+-------------------
+
+By default, ObjectMapper does not map arrays or traversable collections. To map
+each item in a collection (for example, mapping an array of DTOs to an array of
+entities), you **must** explicitly use the ``MapCollection`` transformer:
+
+Example::
+
+    use Symfony\Component\ObjectMapper\Attribute\Map;
+    use Symfony\Component\ObjectMapper\Transform\MapCollection;
+
+    class ProductListInput
+    {
+        #[Map(transform: new MapCollection())]
+        /** @var ProductInput[] */
+        public array $products;
+    }
+
+With this configuration, ObjectMapper maps each item in the ``products`` array
+according to the usual mapping rules. Without ``transform: new MapCollection()``,
+the array is left unchanged.
+
+.. versionadded:: 7.4
+
+    The ``MapCollection`` transformer was introduced in Symfony 7.4.
+
 Mapping Multiple Targets
 ------------------------