feat: better compiler warnings for non-reactive dependencies of reactive statements

[Rich-Harris]

closes #9287. Right now, this causes a test failure, because of a case where we don't know that a binding is state until we've completed the analysis phase. Ideally, we would have a complete picture of state vs non-state by the time scopes have been generated — I've been meaning to fix that for a while now, and this forces the issue

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