Logs errors when GitHub script fails

[ErikSchierboom]

If an error occurs when calling a GitHub script during a workflow run, the exception is displayed: https://github.com/exercism/org-wide-files/runs/6383394202?check_suite_focus=true

However, this is fairly unhelpful, as the actual error is hidden inside the response's data.errors array:

response: {
  ...,
 data: {
      message: 'Validation Failed',
      errors: [Array],
      documentation_url: 'https://docs.github.com/rest/reference/pulls#create-a-pull-request'
    }
  },

It would be super helpful if we could show the actual error messages, likely output as errors via https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#setting-an-error-message

[SaschaMann]

I wouldn't mind it if we displayed both if you find that useful but I think the long-form error can be quite helpful, so I don't think it should be replaced by a shorter message.

[ErikSchierboom]

Both would be great.