fix: add missing GL12 import for GL_CLAMP_TO_EDGE in example

Author: Eatgrapes

example/src/main/java/dev/eatgrapes/live2d/example/Main.java

@@ -16,6 +16,7 @@
 
 import static org.lwjgl.glfw.GLFW.*;
 import static org.lwjgl.opengl.GL11.*;
+import static org.lwjgl.opengl.GL12.GL_CLAMP_TO_EDGE;
 
 public class Main {
     private long window;