Describe the bug

When this plugin is installed, it impacts in particular, the WordPress Featured Image block (and more specifically the Cover block using a Featured Image as the image source). We tracked this down to the plugin adding a post-thumbnail image size within wp-document-revisions/includes/class-wp-document-revisions.php

Steps to reproduce the behavior

1. Install Document Revisions and Activate
2. Using the Site Editor in a block theme, create a template and insert a cover image block to the template and select featured image and the thumbnail source
3. Publish your template and you'll see that the block is loading the 150x150 (or whatever is set as 'thumbnail') to the block. No setting in WordPress currently to change/specify image resolution or source selection

Expected behavior

We don't actually see a way to override this through filters; adding a size called post-thumbnail causes the cover image block to use that size instead of full.

Document revisions itself doesn't appear to use this size on the frontend; perhaps it was added it to handle displaying the media in the admin?