Updates related to Dxc update

Shaders/Instanced.azsl

@@ -1,3 +1,4 @@
+#include <Atom/Features/SrgSemantics.azsli>
 #include <viewsrg.srgi>
 
 struct CubeTransform

Shaders/RHI/BindlessPrototype.shader

@@ -20,5 +20,6 @@
           "type": "Fragment"
         }
       ]
-    }
+    },
+    "DisabledRHIBackends": ["metal"]
 }