Remove Bojhan as maintainer for Usability topic

xjm → credited Bojhan → .

Bohjan, I learned a TON from you that I still apply in my work as a core committer every day. Thank you for everything!

Thank you @Bojhan for all you've done with Drupal!

Among other things, thank you for your help removing the overlay!

@Bojhan, thank you for all your work on Drupal. I've had the pleasure to read your comments while triaging issues and I found them to be very helpful. And thanks for taking the time to reply.

Thanks and best wishes!

Committed to the active branches and updated the project node, google group, slack channel.

xjm → closed merge request !12784

Automatically closed - issue fixed for 2 weeks with no activity.