input: Write a Python function to create a simple GUI window with a label and a button using tkinter, where clicking the button changes the label text.
  assert create_gui_window() == "GUI created with a button that changes label text on click"
  assert isinstance(create_gui_window(), tkinter.Tk)
output: import tkinter as tk
  
  def create_gui_window():
      def on_button_click():
          label.config(text="Button Clicked!")
  
      window = tk.Tk()
      window.title("Simple GUI")
  
      label = tk.Label(window, text="Hello, World!")
      label.pack()
  
      button = tk.Button(window, text="Click Me", command=on_button_click)
      button.pack()
  
      window.mainloop()
      return window