[lvgl] Don't just throw key error if someone types a bad layout type (#7722)

Co-authored-by: Clyde Stubbs <2366188+clydebarrow@users.noreply.github.com>

esphome/components/lvgl/schemas.py

@@ -391,7 +391,9 @@ def container_validator(schema, widget_type: WidgetType):
             add_lv_use(ltype)
         if value == SCHEMA_EXTRACT:
             return result
-        result = result.extend(LAYOUT_SCHEMAS[ltype.lower()])
+        result = result.extend(
+            LAYOUT_SCHEMAS.get(ltype.lower(), LAYOUT_SCHEMAS[df.TYPE_NONE])
+        )
         return result(value)
 
     return validator