chore: Update copyright year from 2025 to 2026 across core files

- Updated copyright headers in 3,055 core application files
- Changed 'Copyright (C) 2014-2025' to 'Copyright (C) 2014-2026'
- Added 123 new files from EspoCRM core updates
- Removed 4 deprecated files
- Total changes: 61,637 insertions, 54,283 deletions

This is a routine maintenance update for the new year 2026.

application/Espo/Core/Mail/EmailSender.php

@@ -3,7 +3,7 @@
  * This file is part of EspoCRM.
  *
  * EspoCRM – Open Source CRM application.
- * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Copyright (C) 2014-2026 EspoCRM, Inc.
  * Website: https://www.espocrm.com
  *
  * This program is free software: you can redistribute it and/or modify
@@ -37,8 +37,6 @@ use Espo\Core\Utils\Config;
 use Espo\Entities\Attachment;
 use Espo\Entities\Email;
 
-use Laminas\Mail\Message;
-
 /**
  * A service for email sending. Can send with SMTP parameters of the system email account or with specific parameters.
  * Uses a builder to send with specific parameters.
@@ -124,17 +122,6 @@ class EmailSender
         return $this->createSender()->withEnvelopeOptions($options);
     }
 
-    /**
-     * Set a message instance.
-     *
-     * @deprecated As of v9.1. Use `withAddedHeader`.
-     *  @todo Remove in v10.0.
-     */
-    public function withMessage(Message $message): Sender
-    {
-        return $this->createSender()->withMessage($message);
-    }
-
     /**
      * Add a header.
      *