Removes the Manage Sites column from the licenses table on customer purchase history page
<?php
/**
 * Plugin Name: Easy Digital Downloads - Remove Manage Sites
 * Description: Removes the Manage Sites column from the licenses table on customer purchase history page
 * Author: Kyle Maurer
 * Author URI: https://easydigitaldownloads.com/
 * Version: 1.0
 */

function kjm_remove_manage_sites_link() {
	if ( isset( $_GET['action'] ) && $_GET['action'] == 'manage_licenses' ) {
		add_filter( 'edd_sl_force_activation_increase', '__return_true' );
	}
}
add_action( 'wp_head', 'kjm_remove_manage_sites_link' );
To implement this snippet on your site, create a brand new, empty WordPress plugin and paste the above code inside.