Describe your change

• Fix a bug or typo in an existing algorithm.
• Add or change doctests.
• Add an algorithm.
• Documentation change.

This change fixes a precision issue in maths/continued_fraction.py. The previous implementation used floor(numerator / denominator), which converted large integers to floating-point numbers and could produce inaccurate results or overflow.

The implementation now uses integer floor division (numerator // denominator), avoiding floating-point conversion while preserving the intended behavior.

Two regression doctests were added to cover large integer inputs, including values that exceed the range of normal floating-point representation.

Issue: Fixes #15655

Checklist

• I have read [CONTRIBUTING.md](https://github.com/TheAlgorithms/Python/blob/master/CONTRIBUTING.md).
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
• This pull request resolves an open issue and includes the closing keyword and issue number above.