Problem/Motivation
It loads all workflow only to add their cache tag, as any workflow might influence the access check.
That is slow (causes an extra config findByPrefix() query) and loads all those config entities, and it's also incorrect, as a new workflow might be added.
Steps to reproduce
Proposed resolution
Replace with a workflow_list cache tag. That said, this alone won't help, since the implementation then again loads all workflow entities.
However, we already have an API for this that doesn't require looping over them:
\Drupal\content_moderation\ModerationInformation::canModerateEntitiesOfEntityType and \Drupal\content_moderation\ModerationInformation::shouldModerateEntitiesOfBundle.
That relies on cached entity type and bundle information.