chore: do not run no-reactive-reassign rule on Svelte 5 with runes

[baseballyama]

The Svelte 5 compiler throws an error if a $derived value is reassigned. For object values, it’s better to use const instead of let. This will be addressed by #985

<script>
  let count = $state(1);
	let double = $derived(count * 2);

	let obj = $state({ foo: 1 });
	let derivedObj = $derived( { ...obj, bar: true });

	function invalid() {
		double = double + 1;
		derivedObj.bar = false;
	}
</script>

https://svelte.dev/playground/hello-world?version=5.17.3#H4sIAAAAAAAAE22PwU7EMAxEf8WyOLRQBZVjdheJGzc-gHBIGlfKKptUiVtAVf8dZdstHLhZM2_G9oxBXwglvpL3ET5j8hYqso7J1thg7zxllO8z8vdQuCJgc0u9DIPIE3kumtGZ_tO7GJgCZ5R4zF1yAz-rAOCJoYtjYDjBXWbNVLX1QQXFxbFxNJ6KZSm5iWy1svfwdIU2LJrzb3yGPkYJLSx_etb028rdumAGIUQ05waMThI4jbSlguJ-DB27GMCFSXtnqxrmoiver9qGB2gPm7PvEUYnOEGvfaaruahwfNwfxwaZvhhl2bl8LD9gOIRsggEAAA==

[pkg-pr-new]

Open in Stackblitz

npm i https://pkg.pr.new/eslint-plugin-svelte@1014

commit: b4eb6bf

[ota-meshi]

That's great! Thank you!