Update dependencies on '6.4' in qt/qtlanguageserver

Change-Id: I85bcbf8b2617e8c82d2bccb27cbc677671509cad
Reviewed-by: Qt Submodule Update Bot <qt_submodule_update_bot@qt-project.org>

dependencies.yaml

 dependencies:
   ../qtbase:
-    ref: 1af74fffd0e11f843afe61240b6b4dabecc1821b
+    ref: a2334fd51099333a5f86ec3f57498d3f394d105e
     required: true