refactor(DT-3906): Delete unused Svelte 4 scaffolding (carved from #3370 - Part 1)#3372

tegan-temporal merged 2 commits intocodefreeze-05.01.26temporalio/ui:codefreeze-05.01.26from

DT-3906-svelte-5-cleanup-deletionstemporalio/ui:DT-3906-svelte-5-cleanup-deletionsCopy head branch name to clipboard