Fix test_build_components crash with top-level !include test files

The IncludeFile representer added in #15549 defers !include resolution,
but the component test scripts assumed load_yaml always returns a dict.
Test files using top-level !include (e.g. usb_uart) caused a TypeError:
'argument of type IncludeFile is not iterable'.

Resolve IncludeFile objects by calling .load() before processing.

script/analyze_component_buses.py

@@ -221,6 +221,9 @@ def analyze_yaml_file(yaml_file: Path) -> dict[str, Any]:
 
     try:
         data = yaml_util.load_yaml(yaml_file)
+        # Top-level !include returns an IncludeFile that must be resolved
+        if isinstance(data, yaml_util.IncludeFile):
+            data = data.load()
         result["loaded"] = True
     except Exception:  # pylint: disable=broad-exception-caught
         return result

script/merge_component_configs.py

@@ -27,6 +27,7 @@ sys.path.insert(0, str(Path(__file__).parent.parent))
 
 from esphome import yaml_util
 from esphome.config_helpers import merge_config
+from esphome.yaml_util import IncludeFile
 from script.analyze_component_buses import PACKAGE_DEPENDENCIES, get_common_bus_packages
 
 # Prefix for dependency markers in package tracking
@@ -46,7 +47,12 @@ def load_yaml_file(yaml_file: Path) -> dict:
     if not yaml_file.exists():
         raise FileNotFoundError(f"YAML file not found: {yaml_file}")
 
-    return yaml_util.load_yaml(yaml_file)
+    data = yaml_util.load_yaml(yaml_file)
+    # Top-level !include (e.g., `!include common.yaml`) returns an IncludeFile
+    # that must be resolved before we can work with it as a dict.
+    if isinstance(data, IncludeFile):
+        data = data.load()
+    return data
 
 
 @lru_cache(maxsize=256)