ui: fix crash caused by double shader unload in CameraView (#36778)

fix double free isuue

selfdrive/ui/mici/onroad/cameraview.py

@@ -197,6 +197,7 @@ class CameraView(Widget):
     # Clean up shader
     if self.shader and self.shader.id:
       rl.unload_shader(self.shader)
+      self.shader.id = 0
 
     self.frame = None
     self.available_streams.clear()