add more rune ts tests

Author: baseballyama

tests/fixtures/parser/ast/svelte5/ts-$derived01-input.svelte

@@ -0,0 +1,10 @@
+<script lang="ts">
+  let count = $state(0);
+  const doubled = $derived(count * 2);
+</script>
+
+<button on:click="{() => count++}">
+  {doubled}
+</button>
+
+<p>{count} doubled is {doubled}</p>