[REF] Remove pass-by-reference & always empty param

Once #17982 is merged there are only 2 places that call this function. In both
places
1) they instantiate an empty values array just to pass in
2) we can see they don't use input or ids afterwards, so they don't need to be passed by reference

CRM/Contribute/BAO/Contribution.php

@@ -4609,9 +4609,8 @@ public static function completeOrder($input, &$ids, $objects, $transaction = NUL
    * @throws \CiviCRM_API3_Exception
    * @throws \Exception
    */
-  public static function sendMail(&$input, &$ids, $contributionID, &$values,
-                                  $returnMessageText = FALSE) {
-
+  public static function sendMail($input, $ids, $contributionID, $returnMessageText = FALSE) {
+    $values = [];
     $contribution = new CRM_Contribute_BAO_Contribution();
     $contribution->id = $contributionID;
     if (!$contribution->find(TRUE)) {

CRM/Contribute/Form/Task/PDF.php

@@ -184,7 +184,6 @@ public function postProcess() {
       // CRM_Contribute_BAO_Contribution::composeMessageArray expects mysql formatted date
       $objects['contribution']->receive_date = CRM_Utils_Date::isoToMysql($objects['contribution']->receive_date);
 
-      $values = [];
       if (isset($params['from_email_address']) && !$elements['createPdf']) {
         // If a logged in user from email is used rather than a domain wide from email address
         // the from_email_address params key will be numerical and we need to convert it to be
@@ -196,8 +195,7 @@ public function postProcess() {
         $input['receipt_from_name'] = str_replace('"', '', $fromDetails[0]);
       }
 
-      $mail = CRM_Contribute_BAO_Contribution::sendMail($input, $ids, $objects['contribution']->id, $values,
-        $elements['createPdf']);
+      $mail = CRM_Contribute_BAO_Contribution::sendMail($input, $ids, $objects['contribution']->id, $elements['createPdf']);
 
       if ($mail['html']) {
         $message[] = $mail['html'];

api/v3/Contribution.php

@@ -393,7 +393,7 @@ function _civicrm_api3_contribute_format_params($params, &$values) {
  * @throws Exception
  */
 function civicrm_api3_contribution_sendconfirmation($params) {
-  $ids = $values = [];
+  $ids = [];
   $allowedParams = [
     'receipt_from_email',
     'receipt_from_name',
@@ -405,7 +405,7 @@ function civicrm_api3_contribution_sendconfirmation($params) {
   ];
   $input = array_intersect_key($params, array_flip($allowedParams));
   $input['is_email_receipt'] = TRUE;
-  CRM_Contribute_BAO_Contribution::sendMail($input, $ids, $params['id'], $values);
+  CRM_Contribute_BAO_Contribution::sendMail($input, $ids, $params['id']);
 }
 
 /**