docs: fix incorrect startTransition usage in server-functions example

[DeveloperViraj]

Closes #8158

Fix incorrect startTransition usage in docs

The example in the Server Functions page calls a server action inside startTransition, but the state updates after the await aren’t wrapped in a new transition. React’s docs mention that post-await state updates aren’t included automatically, so this updates the snippet to wrap them in another startTransition for correctness.

This brings the example in line with the recommended behavior.

[github-actions[bot]]

Size changes

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