chore: remove unused override

src/morphist_viewer.cpp

@@ -16,10 +16,6 @@ MorphistViewer::MorphistViewer(const char *title, int width,
 {
 }
 
-// void MorphistViewer::keyboard(int key, int scancode, int action, int mods)
-// {
-// }
-
 void MorphistViewer::process_imgui()
 {
     ImGui::Spacing();

src/morphist_viewer.hpp

@@ -13,9 +13,6 @@ protected:
     //! this function handles mouse button presses
     void mouse(int button, int action, int mods) override;
 
-    //! this function handles keyboard events
-    // void keyboard(int key, int code, int action, int mod) override;
-
     //! draw the scene in different draw modes
     void process_imgui() override;