Empty lang attribute detected as not well-formed #299

Hello,

I am using Pa11y-CI with HTML_CodeSniffer to scan my Drupal website and it returned:

The language specified in the lang attribute of this element does not appear to be well-formed.

   (#comment-30 > footer > p > span:nth-child(1) > span)

   <span lang="" typeof="schema:Person" property="schema:name" datatype="">Anonymous (non vérifié)</span>

You can see the "problem" when there is a comment, example: https://florent-torregrosa.fr/blog/headers-http-pour-la-securite-avec-drupal

First I opened an issue on Drupal core: https://www.drupal.org/project/drupal/issues/3203292 but as said in the comment https://www.drupal.org/project/drupal/issues/3203292#comment-14144276, an empty lang attribute is allowed in HTML specification.

Then I opened an issue on Pa11y-CI pa11y/pa11y-ci#146 to be redirected here.

• Pa11y-CI config: https://gitlab.com/florenttorregrosa-drupal/docker-drupal-project/-/blob/9.x/scripts/tests/pa11y/pa11y-dev.json
• Docker image I use to run Pa11y-CI: https://hub.docker.com/r/florenttorregrosa/pa11y-ci (source: https://gitlab.com/florenttorregrosa-docker/images/docker-pa11y-ci)
• Pa11y-CI version: 2.4.1 (https://gitlab.com/florenttorregrosa-docker/images/docker-pa11y-ci/-/jobs/1312070120)

Thanks for any help.