fix(turbo-rcstr): allow the napi feature on wasm targets
napi v3 supports wasm32-wasip1-threads, so the hard compile_error! rejecting
the combination is obsolete. Removing it, turbo-rcstr/napi and everything built
on it (turbopack-node/worker_pool, next-api/worker_pool, next-napi-bindings)
compiles for wasm.
Co-authored-by: Luke Sandberg <210140+lukesandberg@users.noreply.github.com>