Fix "Maximum number of collection aliases (128) exceeded"
The "check code" internal job has started failing (from 20 May) with
```
PHP Fatal error: Uncaught Symfony\Component\Yaml\Exception\ParseException:
Maximum number of collection aliases (128) exceeded.
This limit can be increased via the Parser constructor at line 1582 (near "- *phpunit-tests-exist-rule")
in /builds/issue/gitlab_templates-3572395/vendor/symfony/yaml/ParserState.php:66
...
#8 /builds/issue/gitlab_templates-3572395/scripts/yml-keyword-order.php(86): Symfony\Component\Yaml\Yaml::parse('###############...', 512)
```
[Here is the log](https://git.drupalcode.org/issue/gitlab_templates-3572395/-/jobs/9893830#L158)
See [this slack conversation](https://drupal.slack.com/archives/C08CJ9K74MB/p1779274539709299) for details
issue