fix: check for null in isEmptyObject

Because of course `typeof null` is `'object'`

src/datasource/queries/QueryBuilder.ts

@@ -690,7 +690,7 @@ export default class QueryBuilder<Info extends TableInfo> {
   }
 
   private isEmptyObject(value: unknown): boolean {
-    return typeof value === 'object' && Object.keys(value).length === 0
+    return typeof value === 'object' && value !== null && Object.keys(value).length === 0
   }
 
   private valueToSql(