fix: compiler warnings

src/window/Display.cpp

@@ -21,7 +21,6 @@
 namespace Display {
 
 static GLFWwindow* window;
-static bool closeRequested = false;
 
 static int lastWidth = 0, lastHeight = 0;
 static float aspectRatio;
@@ -83,7 +82,7 @@ bool isCloseRequested() {
 	return glfwWindowShouldClose(window);
 }
 
-const bool isMouseDown(int button) {
+bool isMouseDown(int button) {
 	return glfwGetMouseButton(window, button);
 }