fix(list-header): match background with designs (#30058)

core/src/components/item-options/item-options.ionic.scss

@@ -7,6 +7,8 @@
 .item-options-ionic {
   align-items: center;
 
+  background: #{globals.$ion-primitives-base-white};
+
   gap: globals.$ion-space-100;
 }
 

core/src/components/list-header/test/basic/index.html

@@ -82,6 +82,10 @@
       </ion-content>
     </ion-app>
 
-    <style></style>
+    <style>
+      ion-content {
+        --background: #f1f1f1;
+      }
+    </style>
   </body>
 </html>

core/src/components/list/list.ionic.scss

@@ -9,8 +9,6 @@ ion-list {
 
   display: block;
 
-  background: #{globals.$ion-primitives-base-white};
-
   contain: content;
   list-style-type: none;
 }