fix: silence $inspect errors when the effect is about to be destroyed

[Rich-Harris]

#16386 got me thinking — what if instead of making these errors less scary we just didn't show them?

In this PR, if an error occurs while reading $inspect(value), we don't print it immediately. Instead, we stash it. Then, in a sibling render effect, we read the value again (so that the two effects have the same dependencies) and log the error if it occurred.

In 99% of cases (the cases like #16280 (comment)) the render effect will be destroyed before this happens. In the remaining 1%, the error is still logged, with the same stack trace, just a nanosecond later.

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Latest commit: 8d6875f

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Playground

pnpm add https://pkg.pr.new/svelte@16391