UI: show blocking popup when auto execution of scripts is disabled.

This is important information, and it was easily missed at the top/bottom of
the screen.

Ref T57197.

source/blender/editors/space_script/script_ops.c

@@ -44,7 +44,6 @@ void script_operatortypes(void)
 {
 	WM_operatortype_append(SCRIPT_OT_python_file_run);
 	WM_operatortype_append(SCRIPT_OT_reload);
-	WM_operatortype_append(SCRIPT_OT_autoexec_warn_clear);
 }
 
 void script_keymap(wmKeyConfig *UNUSED(keyconf))