Keep the ability to search emailed reports for random test failures

Problem/Motivation

It is no longer possible to search emails for test failures for the frequency of random test failures.

Here is a screenshot of an email I received. The link for the failure in this email is, https://git.drupalcode.org/project/drupal/-/jobs/268447, which goes to a page with the console output for all tests. One then has to scroll or search for the failure(s).

Steps to reproduce

Proposed resolution

Add the output of all test failures to the notification email.

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet