Fix long error in the app iframe cannot be fully scrolled (#7203)

packages/runner/src/iframe/iframe.scss

@@ -1,6 +1,6 @@
 .runner {
   .iframes-container {
-    position: fixed;
+    position: absolute;
 
     &.has-error {
       width: 100%;

packages/runner/src/iframe/iframes.jsx

@@ -25,7 +25,6 @@ export default class Iframes extends Component {
         className={cs('iframes-container', { 'has-error': !!scriptError })}
         style={{
           top: headerHeight,
-          left: this.props.state.absoluteReporterWidth,
         }}
       >
         <div