Add comprehensive test coverage for maths.abs module

[raman1236]

• Added test_abs.py with pytest-compatible tests- Tests cover abs_val, abs_min, abs_max, and abs_max_sort functions- Includes edge cases, error conditions, and consistency checks
• Follows existing test patterns in the repository- Improves test coverage for issue Improve our test coverage #9943

Describe your change:

This PR adds comprehensive unit tests for the maths.abs module to improve test coverage.

Changes Made:

• Added test_abs.py with pytest-compatible tests
• Tests cover abs_val, abs_min, abs_max, and abs_max_sort functions
• Includes edge cases, error conditions, and consistency checks
• Follows existing test patterns in the repository
• Improves test coverage for issue Improve our test coverage #9943

Test Coverage Added:

• 143 lines of comprehensive test code
• Tests for positive, negative, and zero values
• Error condition testing for empty lists
• Consistency checks between abs_max and abs_max_sort functions
• Edge case handling and boundary value testing

Fixes #9943

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist:

• I have read 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.
• If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".