Update CI configuration for coverage reporting and token addition

[sni10]

This pull request updates the CI workflow to improve test coverage reporting and artifact management. The main changes are focused on expanding the coverage report formats, securely uploading coverage results to Codecov, and making coverage reports available as CI artifacts.

Test coverage and reporting improvements:

• The pytest command now generates an HTML coverage report in addition to the existing XML and terminal reports, making it easier to review coverage results visually.

CI artifact management and Codecov integration:

• The Codecov upload step now uses a token from GitHub secrets for secure authentication.
• A new step uploads both the XML and HTML coverage reports as CI artifacts, so they can be downloaded and reviewed after the workflow runs.

[codecov-commenter]

Welcome to Codecov 🎉

Once you merge this PR into your default branch, you're all set! Codecov will compare coverage reports and display results in all future pull requests.

ℹ️ You can also turn on project coverage checks and project coverage reporting on Pull Request comment

Thanks for integrating Codecov - We've got you covered ☂️