Simplify the native dispatch and CI cache wiring

A cache-arduino8266 composite action mirrors cache-esp-idf (one key
resolver, dev-writes/PR-restores) and both jobs pin
ESPHOME_ARDUINO8266_PREFIX so YAML and Python agree on the path by
construction. esp32 provides the native_toolchain_module hook, so the
shared dispatcher never names a backend and the unclaimed-native raise
loses its esp-idf carve-out; the esp8266 decode and run_compile hooks
resolve through the same seam. run_compile resolves ccache once and
threads it to the generator, env, and idedata; the compdb rule names
follow the shared kinds; the pio-options warner inlines into the driver
and derives its consumed set from the core routing constant; the
per-toolchain CI narrowing shares one body; create_components_graph is
memoized per run; the decode rate-limit drops its math sentinel.

script/determine-jobs.py

@@ -50,6 +50,7 @@ from __future__ import annotations
 
 import argparse
 from collections import Counter
+from collections.abc import Callable
 from enum import StrEnum
 from functools import cache
 import json
@@ -595,12 +596,23 @@ def esp32_platformio_components_to_test(branch: str | None = None) -> list[str]:
     Returns:
         Sorted list of component names to compile.
     """
+    return _native_components_to_test(
+        branch, ESP32_PLATFORMIO_TEST_COMPONENTS, _esp32_platformio_path_or_file_trigger
+    )
+
+
+def _native_components_to_test(
+    branch: str | None,
+    test_set: frozenset[str] | set[str],
+    infra_trigger: Callable[[list[str]], bool],
+) -> list[str]:
+    """The shared narrowing rule for the per-toolchain smoke-test jobs."""
     files = changed_files(branch)
 
-    if core_changed(files) or _esp32_platformio_path_or_file_trigger(files):
-        return sorted(ESP32_PLATFORMIO_TEST_COMPONENTS)
+    if core_changed(files) or infra_trigger(files):
+        return sorted(test_set)
 
-    return sorted(ESP32_PLATFORMIO_TEST_COMPONENTS & _changed_components_closure(files))
+    return sorted(test_set & _changed_components_closure(files))
 
 
 def should_run_esp32_platformio(branch: str | None = None) -> bool:
@@ -682,12 +694,9 @@ def esp8266_native_components_to_test(branch: str | None = None) -> list[str]:
     list on core or infrastructure changes, otherwise the intersection with
     the changed-component dependency closure (empty list skips the job).
     """
-    files = changed_files(branch)
-
-    if core_changed(files) or _esp8266_native_path_or_file_trigger(files):
-        return sorted(ESP8266_NATIVE_TEST_COMPONENTS)
-
-    return sorted(ESP8266_NATIVE_TEST_COMPONENTS & _changed_components_closure(files))
+    return _native_components_to_test(
+        branch, ESP8266_NATIVE_TEST_COMPONENTS, _esp8266_native_path_or_file_trigger
+    )
 
 
 def determine_cpp_unit_tests(

script/helpers.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import ast
 from collections.abc import Callable
 from dataclasses import dataclass, field
+import functools
 from functools import cache
 import hashlib
 import json
@@ -1248,6 +1249,7 @@ def get_components_graph_cache_key() -> str:
     return hasher.hexdigest()
 
 
+@functools.cache
 def create_components_graph() -> dict[str, list[str]]:
     """Create a graph of component dependencies (cached).