chore: remove obsolete test (#10679)

Checking for expected or unexpected props in 2024 is the job TypeScript, and runtime validation has resulted in false positives previously - therefore leave this out in Svelte 5.
closes #10672

packages/svelte/tests/runtime-browser/custom-elements-samples/no-missing-prop-warnings/_config.js

@@ -1,23 +0,0 @@
-import { test } from '../../assert';
-const tick = () => Promise.resolve();
-
-export default test({
-	dev: true,
-	skip: true, // TODO: needs dev time warning
-	async test({ assert, target }) {
-		/** @type {string[]} */
-		const warnings = [];
-		const warn = console.warn;
-
-		console.warn = (warning) => {
-			warnings.push(warning);
-		};
-
-		target.innerHTML = '<my-app foo=yes />';
-		await tick();
-
-		assert.deepEqual(warnings, ["<my-app> was created without expected prop 'bar'"]);
-
-		console.warn = warn;
-	}
-});

packages/svelte/tests/runtime-browser/custom-elements-samples/no-missing-prop-warnings/main.svelte

@@ -1,9 +0,0 @@
-<svelte:options customElement="my-app" />
-
-<script>
-	export let foo;
-	export let bar;
-</script>
-
-<p>foo: {foo}</p>
-<p>bar: {bar}</p>