Update dependencies on '6.4' in qt/qtlanguageserver

Change-Id: Idad6942fc5f62df0ee676847a7732648aab2b95a
Reviewed-by: Qt Submodule Update Bot <qt_submodule_update_bot@qt-project.org>

dependencies.yaml

 dependencies:
   ../qtbase:
-    ref: c450285c415f6b3ee528cbb3df35dedce157ffff
+    ref: c3ad3ad4195665cf06db09159580cd52dde53901
     required: true