Avoid adding shader buffer descriptors for constant buffers that are not used (#3478)

* Avoid adding shader buffer descriptors for constant buffers that are not used

* Shader cache version

Ryujinx.Graphics.Shader/StructuredIr/StructuredProgramContext.cs

@@ -300,6 +300,11 @@ namespace Ryujinx.Graphics.Shader.StructuredIr
 
             if (operand.Type != OperandType.LocalVariable)
             {
+                if (operand.Type == OperandType.ConstantBuffer)
+                {
+                    Config.SetUsedConstantBuffer(operand.GetCbufSlot());
+                }
+
                 return new AstOperand(operand);
             }