fix: allow accessing snippet in script tag

[paoloricciuti]

Closes #15786

Initially i thought of just changing const with var and effectively the error is gone...however the runtime behaviour is not the same as the value will be undefined before initialisation.

So what i did is revert back to function declaration and then invoking $.prevent_snippet_stringification on the function declaration discarding the return value (i don't like this bit but i couldn't think of a way around)...it still works because we are still changing the toString of the function.

The small bit of inconsistency is that if you invoke toString in the script tag it will not error out but i would say is probably fine since the error is meant for the template rather than the script tag.

Is there a better solution to this?

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🦋 Changeset detected

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[paoloricciuti]

Cc.ing @elliott-with-the-longest-name-on-github

[github-actions]

Playground

pnpm add https://pkg.pr.new/svelte@15789

[paoloricciuti]

Uh right, I meant to remove the if and forgot about it