Use page template instead of custom post type archive

You can create a page template named template-page-projects-archive.php (for example) that contains the following code:

<?php 
/**
 * Template Name: Project Archives
 */

require( locate_template( 'archive-wm_projects.php' ) );

exit();

When editing a page where you’d like to use the archive-wm_projects.php template, just select Project Archives from the template dropdown.