remove Gravity Forms entry

<?php

$sign_in_form_id = 6;
add_action( 'gform_after_submission_' . $sign_in_form_id , 'mu_remove_form_entry' );

/**
* Prevents Gravity Form entries from being stored in the database
* for a specific form. with $sign_in_form_id Id.
*
* @global object $wpdb The WP database object.
* @param array $entry Array of entry data.
*/

function mu_remove_form_entry( $entry ) {

    global $wpdb;
    
    // Prepare variables.
    $lead_id = $entry['id'];
    $lead_table = RGFormsModel::get_lead_table_name();
    $lead_notes_table = RGFormsModel::get_lead_notes_table_name();
    $lead_detail_table = RGFormsModel::get_lead_details_table_name();
    $lead_detail_long_table = RGFormsModel::get_lead_details_long_table_name();
    
    // Delete from lead detail long.
    $sql = $wpdb->prepare( "DELETE FROM $lead_detail_long_table WHERE lead_detail_id IN(SELECT id FROM $lead_detail_table WHERE lead_id = %d)", $lead_id );
    $wpdb->query( $sql );
    
    // Delete from lead details.
    $sql = $wpdb->prepare( "DELETE FROM $lead_detail_table WHERE lead_id = %d", $lead_id );
    $wpdb->query( $sql );
    
    // Delete from lead notes.
    $sql = $wpdb->prepare( "DELETE FROM $lead_notes_table WHERE lead_id = %d", $lead_id );
    $wpdb->query( $sql );
    
    // Delete from lead.
    $sql = $wpdb->prepare( "DELETE FROM $lead_table WHERE id = %d", $lead_id );
    $wpdb->query( $sql );
    
    // Finally, ensure everything is deleted (like stuff from Addons).
    GFAPI::delete_entry( $lead_id );

}