fix: remove 'implements' from class declaration (#14749)

* fix: remove implements from class declaration

* add a smoke test

Author: ciscorn

.changeset/calm-maps-cover.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: remove implements from class declarations

packages/svelte/src/compiler/phases/1-parse/remove_typescript_nodes.js

@@ -115,6 +115,7 @@ const visitors = {
 		if (node.declare) {
 			return b.empty;
 		}
+		delete node.implements;
 		return context.next();
 	},
 	VariableDeclaration(node, context) {

packages/svelte/tests/runtime-browser/samples/typescript-class-and-interface/_config.js

@@ -0,0 +1,3 @@
+import { test } from '../../assert';
+
+export default test({});

packages/svelte/tests/runtime-browser/samples/typescript-class-and-interface/main.svelte

@@ -0,0 +1,5 @@
+<script lang="ts">
+  // TypeScript syntax should not cause compilation failure
+  interface MyInterface {}
+  class MyClass implements MyInterface {}
+</script>