Fix precision problem in metric's testcases

[MooooCat]

Description

The changes in this PR aim to address the issue of Python's floating-point precision causing test failures. This PR sets an absolute tolerance of 1e-9 using the np.isclose function.

Motivation and Context

The original test cases were failing due to Python's floating-point precision issues. This was causing the test cases to fail even though the results were theoretically correct.

By introducing absolute tolerances, we can make the test cases more robust and less likely to fail due to floating-point precision issues.

How has this been tested?

The changes have been tested using testing cases.

Types of changes

• Maintenance (no change in code, maintain the project's CI, docs, etc.)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[Z712023]

It is nice to see np.close() here