Update codecov.yml

[tanvimoharir]

Summary of changes

This is a change to in codecov configurations to prevent failures as those seen post #2693

Closes #2727

Pull Request Checklist

• Changes have tests
• News fragment added in changelog.d/.
  (See documentation for details)

[jaraco]

This change appears to change three different settings in the configuration. Can you explain the purpose of each of those settings?

[tanvimoharir]

This change appears to change three different settings in the configuration. Can you explain the purpose of each of those settings?

The changes are currently adapted from the configurations initially recommended at #2727 (the main change being reducing the threshold )
These are not final and I'm still looking into details of initial failures.

[webknjaz]

@tanvimoharir could you add a change note per https://setuptools.pypa.io/en/latest/development/developer-guide.html#adding-change-notes-with-your-prs?

[tanvimoharir]

@tanvimoharir could you add a change note per https://setuptools.pypa.io/en/latest/development/developer-guide.html#adding-change-notes-with-your-prs?

Added.