Detect use of deprecated base_url (#35353)

* Detect use of deprecated base_url

* Update get_url helper

* Update core migration

* Migrate all tests

tests/components/geofency/test_init.py

@@ -4,6 +4,7 @@ import pytest
 from homeassistant import data_entry_flow
 from homeassistant.components import zone
 from homeassistant.components.geofency import CONF_MOBILE_BEACONS, DOMAIN
+from homeassistant.config import async_process_ha_core_config
 from homeassistant.const import (
     HTTP_OK,
     HTTP_UNPROCESSABLE_ENTITY,
@@ -14,7 +15,7 @@ from homeassistant.setup import async_setup_component
 from homeassistant.util import slugify
 
 # pylint: disable=redefined-outer-name
-from tests.async_mock import Mock, patch
+from tests.async_mock import patch
 
 HOME_LATITUDE = 37.239622
 HOME_LONGITUDE = -115.815811
@@ -148,7 +149,9 @@ async def setup_zones(loop, hass):
 @pytest.fixture
 async def webhook_id(hass, geofency_client):
     """Initialize the Geofency component and get the webhook_id."""
-    hass.config.api = Mock(base_url="http://example.com")
+    await async_process_ha_core_config(
+        hass, {"internal_url": "http://example.local:8123"},
+    )
     result = await hass.config_entries.flow.async_init(
         DOMAIN, context={"source": "user"}
     )