Mock setup_entry in oauth2 tests (#32102)

* Mock setup_entry in oauth2 tests

* Fix scaffold constant

script/scaffold/templates/config_flow_oauth2/tests/test_config_flow.py

@@ -1,4 +1,6 @@
 """Test the NEW_NAME config flow."""
+from asynctest import patch
+
 from homeassistant import config_entries, setup
 from homeassistant.components.NEW_DOMAIN.const import (
     DOMAIN,
@@ -48,6 +50,10 @@ async def test_full_flow(hass, aiohttp_client, aioclient_mock):
         },
     )
 
-    result = await hass.config_entries.flow.async_configure(result["flow_id"])
+    with patch(
+        "homeassistant.components.NEW_DOMAIN.async_setup_entry", return_value=True
+    ) as mock_setup:
+        await hass.config_entries.flow.async_configure(result["flow_id"])
 
     assert len(hass.config_entries.async_entries(DOMAIN)) == 1
+    assert len(mock_setup.mock_calls) == 1