Update CONTRIBUTING.md

Author: f-PLT

CONTRIBUTING.md

@@ -77,7 +77,6 @@ use for testing in this project.
 To get started and to learn more about testing in Python:
 
 - [Getting started with testing](https://realpython.com/python-testing/)
-- [Testing in the contest of Machine Learning](https://fullstackdeeplearning.com/course/2022/lecture-3-troubleshooting-and-testing/)
 - [Pytest Documentation](https://docs.pytest.org/en/stable/how-to/index.html)
 
 ## Docstring and type hinting