Merge branch '6.4' into 7.0

* 6.4:
  [AssetMapper] Added instruction for 'outdated' command

Author: javiereguiluz

frontend/asset_mapper.rst

@@ -248,6 +248,20 @@ computers if some files are missing.
     such as ``@popperjs/core``. The ``download`` option will download both the main
     package *and* its dependencies.
 
+You can check for available updates for your third-party packages by running:
+
+.. code-block:: terminal
+
+    # check for updates for all packages
+    $ php bin/console importmap:outdated
+
+    # check for updates for the given list of packages
+    $ php bin/console importmap:outdated bootstrap lodash
+
+.. versionadded:: 6.4
+
+    The ``importmap:outdated`` command was introduced in Symfony 6.4.
+
 To update third-party packages in your ``importmap.php`` file, run:
 
 .. code-block:: terminal