[core] Dont copy platform source files if there are no entities of that type (#10436)

esphome/config.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import abc
+from collections import defaultdict
 from contextlib import contextmanager
 import contextvars
 import functools
@@ -37,11 +38,13 @@ from esphome.yaml_util import ESPForceValue, ESPHomeDataBase, is_secret
 _LOGGER = logging.getLogger(__name__)
 
 
-def iter_components(config):
+def iter_components(config: ConfigType, platform_counts: defaultdict[str, int]):
     for domain, conf in config.items():
         component = get_component(domain)
         yield domain, component
         if component.is_platform_component:
+            if not platform_counts[domain]:
+                continue
             for p_config in conf:
                 p_name = f"{domain}.{p_config[CONF_PLATFORM]}"
                 platform = get_platform(domain, p_config[CONF_PLATFORM])