Fix confusing useTransition documentation example

Remove isPending state from TabButton component.

Author: Archanachaurasiya30

src/content/reference/react/useTransition.md

@@ -814,13 +814,11 @@ export default function TabContainer() {
 import { useTransition } from 'react';
 
 export default function TabButton({ action, children, isActive }) {
-  const [isPending, startTransition] = useTransition();
+  const [, startTransition] = useTransition();
   if (isActive) {
     return <b>{children}</b>
   }
-  if (isPending) {
-    return <b className="pending">{children}</b>;
-  }
+  
   return (
     <button onClick={() => {
       startTransition(async () => {