Only load Contact Form 7 scripts when the post/page uses the shortcode

contact-form-7-enhancement.php

<?php
/**
 * Contact Form 7
 * Speed enhancement
 *
 * The code below checks for the use of the CF7 shortcode and will remove scripts and styles when it isn't being used
 */
function deviodigital_deregister_contact_form() {
	global $post;
    if ( ! has_shortcode( $post->post_content, 'contact-form-7' ) ) {
        remove_action('wp_enqueue_scripts', 'wpcf7_enqueue_styles');
        remove_action('wp_enqueue_scripts', 'wpcf7_enqueue_scripts');
    }
}
add_action( 'wp', 'deviodigital_deregister_contact_form');
?>