fix: rerun load functions when the number of values of a tracked search parameter changes

[Nic-Polumeyv]

Since #11258, diff_search_params compares each key's values as a set, so navigating from ?x=a&x=a to ?x=a is treated as unchanged and load functions tracking x don't rerun. Comparing the sorted value lists instead catches count changes, still treats reordering as unchanged, and is O(V log V) rather than O(V²).

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[pkg-svelte-dev]

Install the latest version of @sveltejs/kit from b1c5b99:

pnpm add https://pkg.svelte.dev/@sveltejs/kit/c/b1c5b9918c1d91aea3a293283c573ba656252d46

Open in pkg.svelte.dev: https://pkg.svelte.dev/repos/kit/pr/16495

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Latest commit: b1c5b99

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@sveltejs/kit	Patch

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