Simplify shadow tests to use plain functions

Use regular functions instead of helper managers for the fn shadow
tests, since only scope shadowing is being verified.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: NullVoxPopuli

packages/@glimmer-workspace/integration-tests/test/keywords/fn-test.ts

@@ -1,6 +1,5 @@
 import { castToBrowser } from '@glimmer/debug-util';
 import { jitSuite, RenderTest, test } from '@glimmer-workspace/integration-tests';
-import { helperCapabilities, setHelperManager } from '@glimmer/manager';
 
 import { template } from '@ember/template-compiler/runtime';
 import { fn } from '@ember/helper';
@@ -60,19 +59,9 @@ class KeywordFn extends RenderTest {
 
   @test
   'can be shadowed'(assert: Assert) {
-    let fn = setHelperManager(
-      () => ({
-        capabilities: helperCapabilities('3.23', { hasValue: true }),
-        createHelper() {
-          assert.step('shadowed:success');
-          return {};
-        },
-        getValue() {
-          return () => {};
-        },
-      }),
-      {}
-    );
+    let fn = () => {
+      assert.step('shadowed:success');
+    };
 
     let greet = () => {};
 

smoke-tests/scenarios/basic-test.ts

@@ -385,17 +385,15 @@ function basicTest(scenarios: Scenarios, appName: string) {
 
               import Component from '@glimmer/component';
               import { tracked } from '@glimmer/tracking';
-              import { helper } from '@ember/component/helper';
 
               module('{{fn}} as keyword (but it is shadowed)', function(hooks) {
                 setupRenderingTest(hooks);
 
                 test('it works', async function(assert) {
                   // shadows keyword!
-                  const fn = helper(() => {
-                    assert.step('shadowed:fn:create');
-                    return () => {};
-                  });
+                  const fn = () => {
+                    assert.step('shadowed:fn:invoke');
+                  };
 
                   class Demo extends Component {
                     @tracked message = 'hello';
@@ -407,7 +405,7 @@ function basicTest(scenarios: Scenarios, appName: string) {
                   }
 
                   await render(Demo);
-                  assert.verifySteps(['shadowed:fn:create']);
+                  assert.verifySteps(['shadowed:fn:invoke']);
 
                   assert.dom('button').hasText('hello');
                   await click('button');