Fix extraneous scrollbar in device previews (#66494)

Co-authored-by: stokesman <presstoke@git.wordpress.org>
Co-authored-by: t-hamano <wildworks@git.wordpress.org>
Co-authored-by: colorful-tones <colorful-tones@git.wordpress.org>
Co-authored-by: dhruvang21 <dhruvang21@git.wordpress.org>

packages/block-editor/src/components/iframe/style.scss

@@ -1,7 +1,6 @@
 .block-editor-iframe__container {
 	width: 100%;
 	height: 100%;
-	overflow-x: hidden;
 }
 
 .block-editor-iframe__scale-container {