Hardcoded line-length in `pyproject.toml` ignores `copier.yml` configuration

As a developer, I would like the `line-length` setting in `pyproject.toml` 
to dynamically reflect the `max_line_length` value specified in `copier.yml` 
to ensure consistent coding style configurations across projects.

Acceptance Criteria

• Modify the template generation process so that the line-length in pyproject.toml is set based on the max_line_length value from copier.yml.
• Ensure that any change in the max_line_length setting in copier.yml automatically updates the line-length in pyproject.toml.
• Add tests to verify that the line-length in pyproject.toml adjusts according to updates in copier.yml.