This commit refactors the `builds_config.rb` file to handle generating a new todo file. It adds logic to not load the existing todo file when generating a new one, ensuring that the new todo file includes all necessary ignore rules from scratch.

…e rules.

- Update `BuildsConfigTest` to remove the `test_todo_merged` method
- Removed fixture "u" files.

This commit adds a new test case to ensure that the todo file is not loaded when generating the todo file.

- Refactored the code to use `unless` instead of checking if `argv` does not include "--generate-todo"
- Refactored the test to remove unneeded expected value setup.

The commit adds a new test to check whether standardrb's '--generate-todo' generates the correct todo file.

New test case is introduced to validate the to-do list generation when one already exists. It ensures that existing errors will not obstruct the to-do list generation and will be duly reported.

- Refactored the before_setup method to include additional setup steps.
- Updated the generate_todo_existing test to use a separate test folder and fixture folder for better organization.
- Modified file paths in the generate_todo_existing test to reflect the new folder structure.

- Refactored the `test_generate_todo` and `test_generate_todo_existing` methods in the `StandardrbTest` class to use a new helper function called `assert_generate_todo`.

…lready-exists