Add deprecation warning to Somfy integration (#71653)

homeassistant/components/somfy/__init__.py

@@ -77,6 +77,14 @@ async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
 
 async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     """Set up Somfy from a config entry."""
+
+    _LOGGER.warning(
+        "The Somfy integration is deprecated and will be removed "
+        "in Home Assistant Core 2022.7; due to the Somfy Open API deprecation."
+        "The Somfy Open API will shutdown June 21st 2022, migrate to the "
+        "Overkiz integration to control your Somfy devices"
+    )
+
     # Backwards compat
     if "auth_implementation" not in entry.data:
         hass.config_entries.async_update_entry(