examples(with-mongodb): upgrade to tailwind v4 (#83225)
Upgraded to tailwind 4 and updated react version and dependencies.
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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Jiwon Choi <devjiwonchoi@gmail.com>
Co-authored-by: Michael Arguin <michael.arguin@vercel.com>
