Update dependencies on '6.4' in qt/qtlanguageserver

Change-Id: Id12d84078a8bbe8c9c89e6af6a0a71c6d527e5a3
Reviewed-by: Qt Submodule Update Bot <qt_submodule_update_bot@qt-project.org>

dependencies.yaml

 dependencies:
   ../qtbase:
-    ref: bd0d5d44563729c1805bab2877512497d5d90d6a
+    ref: 6dd2dbaef60f9b4ba6fc6faf294c91dabb9604f1
     required: true