display: Remove vestigial Cg-related calls

panda/src/display/graphicsStateGuardian.cxx

@@ -346,15 +346,6 @@ get_supported_geom_rendering() const {
   return _supported_geom_rendering;
 }
 
-/**
- * Returns true if this particular GSG supports the specified Cg Shader
- * Profile.
- */
-bool GraphicsStateGuardian::
-get_supports_cg_profile(const string &name) const {
-  return false;
-}
-
 /**
  * Changes the coordinate system in effect on this particular gsg.  This is
  * also called the "external" coordinate system, since it is the coordinate

panda/src/display/graphicsStateGuardian.h

@@ -228,7 +228,6 @@ PUBLISHED:
   MAKE_PROPERTY(shader_model, get_shader_model, set_shader_model);
 
   virtual int get_supported_geom_rendering() const;
-  virtual bool get_supports_cg_profile(const std::string &name) const;
 
   INLINE bool get_color_scale_via_lighting() const;
   INLINE bool get_alpha_scale_via_texture() const;

panda/src/dxgsg9/wdxGraphicsWindow9.cxx

@@ -240,8 +240,6 @@ close_window() {
     _gsg.clear();
   }
 
-  DXGraphicsStateGuardian9::set_cg_device(nullptr);
-
   _dxgsg->release_swap_chain(&_wcontext);
   WinGraphicsWindow::close_window();
 }