Support error reporting in GitHub Actions

[sanmai]

Please add support for error reporting in GitHub Actions.

For example, like PHPStan or Psalm, or Infection do.

[Ocramius]

From the twitters, for whomever wants to pick up the task: https://github.com/symfony/symfony/blob/f0aa4e7df17d40eadf540c6c3d0f9e6feac67648/src/Symfony/Component/Console/CI/GithubActionReporter.php#L21

[Ocramius]

Cross-linking an implementation example: https://github.com/Roave/BackwardCompatibilityCheck/blob/54de7e8a200e458c3c449b0ff41d669a0eb1a88a/src/Formatter/GithubActionsFormatter.php

Again, just for any takers :P