Add service to reload scenes from configuration.yaml (#25680)

* Allow reloading scenes

* Update requirements

* address comments

* fix typing

* fix tests

* Update homeassistant/components/homeassistant/scene.py

Co-Authored-By: Martin Hjelmare <marhje52@kth.se>

* Address comments

tests/components/homeassistant/test_scene.py

@@ -0,0 +1,30 @@
+"""Test Home Assistant scenes."""
+from unittest.mock import patch
+
+from homeassistant.setup import async_setup_component
+
+
+async def test_reload_config_service(hass):
+    """Test the reload config service."""
+    assert await async_setup_component(hass, "scene", {})
+
+    with patch(
+        "homeassistant.config.load_yaml_config_file",
+        autospec=True,
+        return_value={"scene": {"name": "Hallo", "entities": {"light.kitchen": "on"}}},
+    ), patch("homeassistant.config.find_config_file", return_value=""):
+        await hass.services.async_call("scene", "reload", blocking=True)
+        await hass.async_block_till_done()
+
+    assert hass.states.get("scene.hallo") is not None
+
+    with patch(
+        "homeassistant.config.load_yaml_config_file",
+        autospec=True,
+        return_value={"scene": {"name": "Bye", "entities": {"light.kitchen": "on"}}},
+    ), patch("homeassistant.config.find_config_file", return_value=""):
+        await hass.services.async_call("scene", "reload", blocking=True)
+        await hass.async_block_till_done()
+
+    assert hass.states.get("scene.hallo") is None
+    assert hass.states.get("scene.bye") is not None