test: adjust unscoped auth

Author: clydin

tests/legacy-cli/e2e/tests/commands/add/secure-registry.ts

@@ -10,7 +10,7 @@ export default async function () {
     // The environment variable has priority over the .npmrc
     delete process.env['NPM_CONFIG_REGISTRY'];
     const packageManager = getActivePackageManager();
-    const supportsUnscopedAuth = packageManager !== 'bun' && packageManager !== 'npm';
+    const supportsUnscopedAuth = packageManager === 'yarn';
     const command = ['add', '@angular/pwa', '--skip-confirmation'];
 
     await expectFileNotToExist('public/manifest.webmanifest');