Add database migration for removing OAuth1 tables

app/migrations/Version20210609191822.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * @copyright   2021 Mautic Contributors. All rights reserved.
+ * @author      Mautic
+ * @link        https://mautic.org
+ * @license     GNU/GPLv3 http://www.gnu.org/licenses/gpl-3.0.html
+ */
+
+namespace Mautic\Migrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\Exception\SkipMigration;
+use Mautic\CoreBundle\Doctrine\AbstractMauticMigration;
+
+final class Version20210609191822 extends AbstractMauticMigration
+{
+    /**
+     * Mautic 4 removed OAuth1 support, so we drop those tables.
+     */
+    public function up(Schema $schema): void
+    {
+        $schema->dropTable('oauth1_access_tokens');
+        $schema->dropTable('oauth1_consumers');
+        $schema->dropTable('oauth1_nonces');
+        $schema->dropTable('oauth1_request_tokens');
+    }
+}