fix: prevent reactive statement reruns

[dummdidumm]

• run reactive statements only once per tick, even when they have indirect cyclic dependencies. Made possible by adding an array to the component context, which is filled with identifiers of the reactive statements, and which is cleared after all have run. Reactive statements rerunning before that will bail early if they detect they're still in the list
• part of the solution is to run all reactive statements, and then all render effects, which also fixes Svelte 5 changes the update order of $: and {#key} in Svelte 4 Components #10597

FYI @Rich-Harris - okay to merge? This touches some of the stuff you're refactoring

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🦋 Changeset detected

Latest commit: 5583399

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[Rich-Harris]

yeah, i'll fix the conflicts. this is still in draft though, is it ready? approved if so

[dummdidumm]

Yeah it's ready, just put it in draft Mode to prevent accidental merges before you respond