computer_science/recursion/1_factorial: fixed bug where test could fail for 25! despite correct implementation

[camille-lanuel]

Because

When testing 25!, there could be rounding errors when the implemented solution was different from the solution provided by TOP, which resulted in the test to fail despite having a correct implementation.

This PR

• Replaced 25! instead of 18!: 18! is the largest factorial less than 2^53-1 (the precision of a double). Testing with 18! instead of 25! ensures that there will be no such fail.

Issue

Closes #604

Additional Information

Pull Request Requirements

• I have thoroughly read and understand The Odin Project Contributing Guide
• The title of this PR follows the location of change: brief description of change format, e.g. 01_helloWorld: Update test cases
• The Because section summarizes the reason for this PR
• The This PR section has a bullet point list describing the changes in this PR
• If this PR addresses an open issue, it is linked in the Issue section
• If this PR includes any changes that affect the solution of an exercise, I've also updated the solution in the /solutions folder

[JoshDevHub]

Awesome! Thank you for fixing this 🚀