fix: remove buggy validate_dynamic_component check

[Rich-Harris]

Alternative to #12950, closes #12857.

In other contexts, we've decided that it makes more sense to rely on typechecking than to insert runtime checks everywhere:

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I think that goes double when the validation itself is brittle and inconsistently applied (for <svelte:component>, but not for a normal <Component> that's dynamic). We can make our lives simpler here.

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[changeset-bot]

🦋 Changeset detected

Latest commit: 7865d38

The changes in this PR will be included in the next version bump.

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svelte	Patch

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[Conduitry]

👍 I like this solution.