Fix WAM default account code sample (#35007)

sdk/identity/azure-identity-broker/README.md

@@ -59,7 +59,7 @@ client = BlobServiceClient(account_url, credential=credential)
 To bypass the account selection dialog and use the account currently signed into the operating system, set the `use_default_broker_account` argument to `True`. The credential will attempt to silently use the default broker account. If using the default account fails, the credential will fall back to interactive authentication.
 
 ```python
-credential = new InteractiveBrowserBrokerCredential(
+credential = InteractiveBrowserBrokerCredential(
     parent_window_handle=current_window_handle,
     use_default_broker_account=True
 )