fix: remove dropTable auth_access_tokens

There is no such a table in Shield.

Author: kenjis

src/Database/Migrations/2020-12-28-223112_create_auth_tables.php

@@ -140,7 +140,6 @@ public function down(): void
         $this->forge->dropTable('auth_logins', true);
         $this->forge->dropTable('auth_token_logins', true);
         $this->forge->dropTable('auth_remember_tokens', true);
-        $this->forge->dropTable('auth_access_tokens', true);
         $this->forge->dropTable('auth_identities', true);
         $this->forge->dropTable('auth_groups_users', true);
         $this->forge->dropTable('auth_permissions_users', true);