Delete missing demo RTL style (#2231)

Co-authored-by: Paweł Kuna <[email protected]>

.changeset/popular-hairs-unite.md

@@ -0,0 +1,5 @@
+---
+"preview": patch
+---
+
+Delete missing demo RTL style

preview/pages/_includes/layout/css.html

@@ -28,5 +28,5 @@
 <!-- END PLUGINS STYLES -->
 
 <!-- BEGIN DEMO STYLES -->
-<link href="{{ page | relative }}/preview/css/demo{% if layout-rtl %}.rtl{% endif %}{% if environment != 'development' %}.min{% endif %}.css{% if environment != 'development' %}?{{ 'now' | date: '%s' }}{% endif %}" rel="stylesheet"/>
+<link href="{{ page | relative }}/preview/css/demo{% if environment != 'development' %}.min{% endif %}.css{% if environment != 'development' %}?{{ 'now' | date: '%s' }}{% endif %}" rel="stylesheet"/>
 <!-- END DEMO STYLES -->