fix: variant prop

Author: manika-signoz

data/docs/test.mdx

@@ -162,11 +162,11 @@ Default state is **expanded**. Click the header to toggle.
 
 ### Collapsible `lg` variant
 
-<Admonition type="note" variant="lg" title="Large collapsible note">
+<Admonition type="note" size="lg" title="Large collapsible note">
   Large variant, collapsible, starts expanded. `inline code` and [a link](https://signoz.io/docs/).
 </Admonition>
 
-<Admonition type="tip" variant="lg" defaultCollapsed title="Large collapsible tip — starts collapsed">
+<Admonition type="tip" size="lg" defaultCollapsed title="Large collapsible tip — starts collapsed">
   Large variant, collapsible, starts collapsed.
 
   ```bash