Remove duplicate guard from custom renderer fixture

packages/client/ui-sidebar-documentpreview/tests/renderer-loading.client.spec.tsx

@@ -48,7 +48,6 @@ it('lets a non-Office renderer load content, report its version, and reload thro
   }
   const renderSlot: TextPreviewProps['renderSlot'] = (name, input) => {
     if (name !== 'sidebar.right.tab.document') return null
-    if (key !== 'sidebar.right.tab.document') return null
     const owner = input as unknown as OwnerOf<'sidebar.right.tab.document'>
     return <CustomBody content={owner.content} />
   }