make this a runtime test

packages/svelte/test/runtime/samples/inline-style-directive-update-object-property/_config.js

@@ -6,14 +6,14 @@ export default {
 	test({ assert, target, window, component }) {
 		const p = target.querySelector('p');
 		const styles = window.getComputedStyle(p);
-		assert.equal(styles.backgroundColor, 'rgb(0, 128, 0)');
+		assert.equal(styles.backgroundColor, 'green');
 		assert.equal(styles.fontSize, '12px');
 
 		{
 			component.modify = true;
 			const p = target.querySelector('p');
 			const styles = window.getComputedStyle(p);
-			assert.equal(styles.backgroundColor, 'rgb(0, 128, 0)');
+			assert.equal(styles.backgroundColor, 'green');
 			assert.equal(styles.fontSize, '50px');
 		}
 	}