fix: derive results_directory path from results_repo name

[dbuades]

The load_results function includes a results_repo parameter, allowing the use of an alternative Git repository for storing the benchmarking results. This parameter is then passed to the download_of_results function. However, the current implementation requires the alternative repository to be named results, as this name is hardcoded.

This PR updates the code to derive the results_directory path from the repository name, removing the hardcoded requirement and giving more flexibility in naming the alternative repository.

Checklist

• Run tests locally to make sure nothing is broken using make test.
• Run the formatter to format the code using make lint.

[isaac-chung]

Nice catch, thank you!