Null: Remove unused function

src/null_platform.h

@@ -116,7 +116,6 @@ GLFWbool _glfwRawMouseMotionSupportedNull(void);
 void _glfwShowWindowNull(_GLFWwindow* window);
 void _glfwRequestWindowAttentionNull(_GLFWwindow* window);
 void _glfwRequestWindowAttentionNull(_GLFWwindow* window);
-void _glfwUnhideWindowNull(_GLFWwindow* window);
 void _glfwHideWindowNull(_GLFWwindow* window);
 void _glfwFocusWindowNull(_GLFWwindow* window);
 int _glfwWindowFocusedNull(_GLFWwindow* window);

src/null_window.c

@@ -409,10 +409,6 @@ void _glfwRequestWindowAttentionNull(_GLFWwindow* window)
 {
 }
 
-void _glfwUnhideWindowNull(_GLFWwindow* window)
-{
-}
-
 void _glfwHideWindowNull(_GLFWwindow* window)
 {
     if (_glfw.null.focusedWindow == window)