fix: migrated snippet shadowing prop and let directive removal

[paoloricciuti]

Svelte 5 rewrite

Closes #13665

While fixing i also noticed that we were incorrectly removing the let directive in the case where we don't migrate the slot if the let directive were there before the name of the slot.

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[benmccann]

i'm curious, could you just add stuff the queue and flush it at the very end? the code might be simpler if that's possible, but I'm not sure if it would cause things to break and the intermediate flushes are required

if that's not possible then I think we could merge this

[paoloricciuti]

i'm curious, could you just add stuff the queue and flush it at the very end? the code might be simpler if that's possible, but I'm not sure if it would cause things to break and the intermediate flushes are required

if that's not possible then I think we could merge this

Yeah it should be doable...it was just to prevent pushing and then looping if we find the name immediately (which should be the common case imho). Should I do it?

[benmccann]

I think it'd end up being a nice code simplification

[paoloricciuti]

I think it'd end up being a nice code simplification

Aight...let me do it quickly