Code Coverage for PR's #1290
Description
Currently, we don't have any way to expose code coverage reports to PR's.
The goal is to quickly understand if new code is covered by any tests or if changes are not happening on code that is not properly covered which might lead to bc breaks.
The coverage % metric by itself is irrelevant.
https://about.codecov.io/ has a very nice way to display coverage in PR.
Example: sebastianbergmann/phpunit#5992 (comment)
Configuration reference: https://github.com/sebastianbergmann/phpunit/blob/main/.github/workflows/ci.yaml#L187