fix(arborist): don't flag inert optional deps in strict-allow-scripts (#9597)

Fixes #9562.

`strict-allow-scripts` walked the ideal tree and rejected inert optional
deps like `fsevents` on Linux, even though reify removes them before any
install script runs. The shared `collectUnreviewedScripts` walk now
skips inert nodes, so the strict check matches what actually installs.
`approve-scripts` (actual tree) was already correct.