Svelte: Add script for ecosystem CI

code/renderers/svelte/src/__test__/Button.svelte

@@ -1,12 +1,15 @@
 <script lang="ts">
-  import { createEventDispatcher } from 'svelte';
+  interface Props {
+    disabled: boolean;
+    label: string;
+    clicked?: (e: MouseEvent) => void;
+  }
 
-  export let disabled: boolean;
-  export let label: string;
-
-  const dispatch = createEventDispatcher();
+  // When a Svelte 5 component only uses runes, it is typed as a function component.
+  // Others are typed as class components. Hence we need to have tests for both shapes.
+  let { disabled, label, clicked}: Props = $props();
 </script>
 
-<button on:click={(e) => dispatch('clicked', e)} on:dblclick on:mousemove {disabled}>
+<button onclick={clicked} {disabled}>
   {label}
 </button>

code/renderers/svelte/src/__test__/Decorator.svelte

@@ -1,8 +1,14 @@
 <script lang="ts">
-  export let decoratorArg: string;
+  import type { Snippet } from "svelte";
+
+  interface Props {
+    children: Snippet;
+    decoratorArg: string;
+  }
+  let { children, decoratorArg }: Props = $props();
 </script>
 
 <div>
   Decorator: {decoratorArg}
-  <slot />
+  {@render children()}
 </div>

code/renderers/svelte/src/__test__/Decorator2.svelte

@@ -1,8 +1,14 @@
 <script lang="ts">
-  export let decoratorArg2: string;
+  import type { Snippet } from "svelte";
+
+  interface Props {
+    children: Snippet;
+    decoratorArg2: string;
+  }
+  let { children, decoratorArg2 }: Props = $props();
 </script>
 
 <div>
   Decorator: {decoratorArg2}
-  <slot />
+  {@render children()}
 </div>