fix: support TS type assertions (#15642)

fixes #15565

Author: dummdidumm

.changeset/lovely-windows-hang.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: support TS type assertions

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

@@ -94,6 +94,9 @@ const visitors = {
 	TSTypeAliasDeclaration() {
 		return b.empty;
 	},
+	TSTypeAssertion(node, context) {
+		return context.visit(node.expression);
+	},
 	TSEnumDeclaration(node) {
 		e.typescript_invalid_feature(node, 'enums');
 	},

packages/svelte/tests/runtime-runes/samples/typescript/main.svelte

@@ -45,6 +45,7 @@
 	export type { Hello };
 
 	const TypedFoo = Foo<true>;
+	const typeAssertion = <boolean>true;
 </script>
 
 <script>