chore: add Codecov test analytics

[thomasrockhu-codecov]

Pull Request Description

(replace this text with your description)

Hi, Tom from Codecov here. I saw that you used Codecov already, and I thought you could benefit from catching any flaky or failed tests. We released a Test Analytics product that might be helpful and would love your feedback.

---

After creating the pull request: in order to pass the release_notes_updated check you will need to update the "Future Release" section of docs/source/release_notes.rst to include this pull request.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}