Update dependencies on '6.0.0' in qt/qtshadertools

Change-Id: I33ecb6684a796b52318db0c317fe5eb522ad6c24
Reviewed-by: Qt Submodule Update Bot <qt_submodule_update_bot@qt-project.org>

dependencies.yaml

 dependencies:
   ../qtbase:
-    ref: b2ebc2268c1a4093b0771c92e53732a1ad332f1c
+    ref: fc9cda5f08ac848e88f63dd4a07c08b2fbc6bf17
     required: true