[CI] Prune redundant CPU test overhead (#34309)

Co-authored-by: hnyls2002 <lsyincs@gmail.com>

scripts/lint/check_rust_ext_cache_prefix.py

@@ -0,0 +1,66 @@
+#!/usr/bin/env python3
+"""Check that the rust-ext cache key stays in sync across its sites.
+
+The build workflow looks up and saves cache entries under its own prefix and
+hashed inputs; the download action restores with its own. Neither file can
+reference the other, and a mismatch in EITHER half makes every pool silently
+fall back to source builds at install time.
+"""
+
+import re
+import sys
+
+import yaml
+
+BUILD_WORKFLOW = ".github/workflows/_pr-test-rust-ext-build.yml"
+DOWNLOAD_ACTION = ".github/actions/download-rust-ext/action.yml"
+
+_HASH_FILES = re.compile(r"hashFiles\(([^)]*)\)")
+_QUOTED = re.compile(r"'([^']*)'")
+
+
+def hashed_inputs(path: str) -> list[tuple[str, ...]]:
+    """The argument tuple of every ``hashFiles(...)`` cache key in a file."""
+    with open(path, encoding="utf-8") as f:
+        text = f.read()
+    return [tuple(_QUOTED.findall(args)) for args in _HASH_FILES.findall(text)]
+
+
+def main() -> int:
+    with open(BUILD_WORKFLOW, encoding="utf-8") as f:
+        workflow = yaml.safe_load(f)
+    with open(DOWNLOAD_ACTION, encoding="utf-8") as f:
+        action = yaml.safe_load(f)
+
+    # yaml 1.1 parses the `on:` key as boolean True
+    triggers = workflow.get("on", workflow.get(True))
+    save_prefix = triggers["workflow_call"]["inputs"]["cache_key_prefix"]["default"]
+    restore_prefix = action["inputs"]["cache_key_prefix"]["default"]
+
+    if save_prefix != restore_prefix:
+        print("ERROR: rust-ext cache_key_prefix defaults do not match.")
+        print(f"  {BUILD_WORKFLOW} saves under:    {save_prefix}")
+        print(f"  {DOWNLOAD_ACTION} restores with: {restore_prefix}")
+        print("Bump both together, or every pool falls back to source builds.")
+        return 1
+
+    # Adding a file to one key alone permanently misses the other's entries.
+    sites = [(BUILD_WORKFLOW, inputs) for inputs in hashed_inputs(BUILD_WORKFLOW)]
+    sites += [(DOWNLOAD_ACTION, inputs) for inputs in hashed_inputs(DOWNLOAD_ACTION)]
+
+    if not sites:
+        print("ERROR: no hashFiles(...) cache key found; this check is dead.")
+        return 1
+
+    if len({inputs for _, inputs in sites}) > 1:
+        print("ERROR: rust-ext cache key inputs do not match.")
+        for path, inputs in sites:
+            print(f"  {path}: {list(inputs)}")
+        print("Every lookup/save/restore site must hash the same inputs.")
+        return 1
+
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())