Update CFF

[dgarijo]

To reflect the latest citation:

@InProceedings{10.1145/3643991.3644876,
    author="Garijo, Daniel and Arroyo, Miguel and Gonzalez, Esteban and Treude, Christoph and Tarocco, Nicola",
    title="Bidirectional Paper-Repository Tracing in Software Engineering",
    booktitle="To appear in 21st International Conference on Mining Software Repositories",
    year="2024",
    publisher="ACM",
    address="Cham",
    doi="10.1145/3643991.3644876",
    url= {https://dgarijo.com/papers/msr_2024.pdf}
}

Maybe wait a bit until the DOI works.