[dynamicIO] use RSC dynamicness to control partial vs complete PPR result (#81627)
Historically anything dynamic in a prerender would result in a partially
static shell that resumes at runtime. With this change, now partial
shells are only possible when RSC is dynamic. If your client prerender
has any IO but your RSC tree was entirely prerenderable then Next.js
will produce a complete static result and not perform a resume at
runtime. This simplifies how you reason about what will and wil not make
a static page. It also means that anything dynamic in the client layer
will only render in browser.
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Co-authored-by: Hendrik Liebau <mail@hendrik-liebau.de>