fix(examples): resolve hydration mismatch in blog-starter (#87703)
## What?
Add `suppressHydrationWarning` to the `<html>` element in the
blog-starter example.
## Why?
The ThemeSwitcher script runs before React hydration and adds `dark`
class and `data-mode` attribute to the `<html>` element, causing a
hydration mismatch error.
## How?
Add `suppressHydrationWarning` to the `<html>` element to tell React
this mismatch is intentional.
Fixes #74586
Co-authored-by: Joseph <joseph.chamochumbi@vercel.com>