Change @var to @psalm-var to avoid IDE issues

src/Database/Type/ExpressionTypeCasterTrait.php

@@ -49,7 +49,7 @@ trait ExpressionTypeCasterTrait
         $multi = $type !== $baseType;
 
         if ($multi) {
-            /** @var \Cake\Database\Type\ExpressionTypeInterface $converter */
+            /** @psalm-var \Cake\Database\Type\ExpressionTypeInterface $converter */
             return array_map([$converter, 'toExpression'], $value);
         }