Option to opt-out staff members from reciveing emails

[Valentina R]

Requested here: https://bookingwp.com/forums/topic/new-appointment-notification-to-admin-and-staff/

[Željan Topić]

Two options are available here:

1. Admin email notifications are disabled in admin.
2. Use the following filter to only remove staff from receiving emails:

add_action( 'init', 'woocommerce_appointments_disable_staff_emails' );
function woocommerce_appointments_disable_staff_emails() {
    remove_filter( 'woocommerce_email_recipient_admin_new_appointment', array( 'WC_Email_Admin_New_Appointment', 'email_recipients' ), 10, 2 );
    remove_filter( 'woocommerce_email_recipient_admin_appointment_cancelled', array( 'WC_Email_Admin_New_Appointment', 'email_recipients' ), 10, 2 );
}