CScriptLayer: Make pointer parameter in RemoveInstance() const

The pointed to data isn't modified here, so we can mark the parameter as
const to allow it to be used in more scenarios.

src/Core/Resource/Script/CScriptLayer.h

@@ -42,7 +42,7 @@ public:
         }
     }
 
-    void RemoveInstance(CScriptObject *pInstance)
+    void RemoveInstance(const CScriptObject *pInstance)
     {
         const auto it = std::find_if(mInstances.cbegin(), mInstances.cend(),
                                      [pInstance](const auto* instance) { return instance == pInstance; });