[config] Clean build on ESP-IDF when component/platform combos change (#9028)

esphome/core/__init__.py

@@ -512,6 +512,8 @@ class EsphomeCore:
         self.platformio_options: dict[str, str | list[str]] = {}
         # A set of strings of names of loaded integrations, used to find namespace ID conflicts
         self.loaded_integrations = set()
+        # A set of strings for platform/integration combos
+        self.loaded_platforms: set[str] = set()
         # A set of component IDs to track what Component subclasses are declared
         self.component_ids = set()
         # Whether ESPHome was started in verbose mode