Revert "ui(raylib): "exit" btn in text window on PC (#35052)"

This reverts commit f9767d2650.

system/ui/text.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 import re
 import pyray as rl
-from openpilot.system.hardware import HARDWARE, PC
+from openpilot.system.hardware import HARDWARE
 from openpilot.system.ui.lib.button import gui_button, ButtonStyle
 from openpilot.system.ui.lib.scroll_panel import GuiScrollPanel
 from openpilot.system.ui.lib.application import gui_app
@@ -58,12 +58,9 @@ class TextWindow:
     rl.end_scissor_mode()
 
     button_bounds = rl.Rectangle(gui_app.width - MARGIN - BUTTON_SIZE.x, gui_app.height - MARGIN - BUTTON_SIZE.y, BUTTON_SIZE.x, BUTTON_SIZE.y)
-    ret = gui_button(button_bounds, "Exit" if PC else "Reboot", button_style=ButtonStyle.TRANSPARENT)
+    ret = gui_button(button_bounds, "Reboot", button_style=ButtonStyle.TRANSPARENT)
     if ret:
-      if PC:
-        gui_app.close()
-      else:
-        HARDWARE.reboot()
+      HARDWARE.reboot()
     return ret