https://github.com/odoo/odoo/blob/18.0/addons/project_todo/tests/test_todo_ui.py

I created class 

from odoo.tests.common import TransactionCase
from odoo.addons.project_todo.tests.test_todo_ui import TestTodoUi as BaseTestTodoUi
from odoo.tests import tagged, users

@tagged('post_install', '-at_install')
class TestTodoUi(BaseTestTodoUi):
     @unittest.skip("Skipping this test - reason here")
    def test_tour_project_task_activities_split(self):
        # Call the original method if you want to keep the original logic, 
        # or override it with custom behavior
        #super().test_tour_project_task_activities_split()
        
        # Add your custom assertions or changes here
        print("Custom behavior for test_tour_project_task_activities_split")
        pass
    
    @unittest.skip("Skipping this test - reason here")
    def test_tour_todo_main_ui_functions(self):
        # Call the original method if you want to keep the original logic
        #super().test_tour_todo_main_ui_functions()
        
        # Add your custom assertions or changes here
        print("Custom behavior for test_tour_todo_main_ui_functions")
        pass