Checks for pins used in multiple places (#5666)

esphome/core/__init__.py

@@ -526,6 +526,8 @@ class EsphomeCore:
         self.quiet = False
 
     def reset(self):
+        from esphome.pins import PIN_SCHEMA_REGISTRY
+
         self.dashboard = False
         self.name = None
         self.friendly_name = None
@@ -545,6 +547,7 @@ class EsphomeCore:
         self.platformio_options = {}
         self.loaded_integrations = set()
         self.component_ids = set()
+        PIN_SCHEMA_REGISTRY.reset()
 
     @property
     def address(self) -> Optional[str]: