Hi Scott,
Have you checked the Preparing for Confluence 9.0 - EAP out now post? There is a comment by rr1(Preparing for Confluence 9.0 - EAP out now - #568 by rr1) who seems to have had the similar problem…
The solution was to add this snippet here:
<dependency>
<groupId>com.atlassian.confluence.plugins</groupId>
<artifactId>confluence-create-content-api</artifactId>
</dependency>
But I suggest you read the comments yourself to get the full background of the solution.
Regards,
Christian