[Improvement][UI] use relative width for task editor (#16769)

Author: kevinjmh

dolphinscheduler-ui/src/components/modal/index.module.scss

@@ -16,7 +16,7 @@
  */
 
 .container {
-  width: 600px;
+  width: 33%;
 }
 .modal-card {
   max-height: 100vh;