Fixing tests

test/cli/samples/custom-element/expected/Main.js

@@ -67,7 +67,9 @@ assign(Main.prototype, {
 	}
 });
 
+if (!customElements.get("my-element")) {
 	customElements.define("my-element", Main);
+}
 
 Main.prototype._recompute = noop;
 

test/js/samples/css-shadow-dom-keyframes/expected.js

@@ -59,5 +59,7 @@ assign(SvelteComponent.prototype, {
 	}
 });
 
+if (!customElements.get("custom-element")) {
 	customElements.define("custom-element", SvelteComponent);
+}
 export default SvelteComponent;