fix: Apply padding to Snaps UI root element no matter the type (#26850)

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## **Description**

Fixes a problem where padding would not be applied correctly to the
first child of the Snaps UI container. We were expecting all root
elements to be `div`. But many different types of components are allowed
at the root. Quick fix by applying the padding no matter what type the
root element is.

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## **Screenshots/Recordings**

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before and after of your change. -->

### **Before**


![image](https://github.com/user-attachments/assets/4a6680cc-137b-419d-8265-52345d4414cc)


### **After**


![image](https://github.com/user-attachments/assets/8655005b-f37b-44eb-8624-3f6e75250051)

ui/components/app/snaps/snap-ui-renderer/index.scss

@@ -4,7 +4,7 @@
   }
 
   &__container {
-    & > div:first-child {
+    & > *:first-child {
       padding: 16px;
     }
   }