Fix: missing close brace in demo code (#76549)

Upon reading the documentation, I found the demo TypeScript code in
server components section is missing a close brace.

So adding it back to fix the issue. Thanks for reviewing!

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Co-authored-by: JJ Kasper <[email protected]>

Author: LihaoWang

docs/01-app/01-getting-started/07-updating-data.mdx

@@ -44,6 +44,7 @@ export default function Page() {
     'use server'
     // Update data
     // ...
+  }
 
   return <></>
 }