Make pip audit optional

[javidahmed64592]

This pull request introduces minor updates to the CI workflow and development dependencies, primarily to improve reliability and keep dependencies up to date.

CI workflow improvement:

• The pip-audit job in the GitHub Actions workflow now uses continue-on-error: true, allowing the workflow to proceed even if pip-audit encounters issues.

Dependency updates:

• Updated pytest-cov to version 7.1.0 and ruff to version 0.15.7 in the pyproject.toml development dependencies.