Remove unreachable errorf in aside shortcode

layouts/shortcodes/aside.html

@@ -1,7 +1,5 @@
 <aside>
     {{ with .Inner }}
         {{ . | markdownify }}
-    {{ else }}
-        {{ errorf "The aside shortcode needs to be a closing one (similar to the highlight shortcode, see https://gohugo.io/templates/shortcode-templates/#inner" }}
     {{ end }}
 </aside>