Retry os.replace on Windows PermissionError

On Windows, os.replace raises PermissionError when another process
has the target file open. Add exponential backoff retry (5 attempts)
for the concurrent-writers case.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: cpcloud

cuda_core/cuda/core/utils/_program_cache.py

@@ -575,7 +575,16 @@ def __setitem__(self, key: object, value: object) -> None:
                 fh.write(record)
                 fh.flush()
                 os.fsync(fh.fileno())
-            os.replace(tmp_path, target)
+            # On Windows, os.replace can raise PermissionError when another
+            # process holds the target open.  Retry a few times with backoff.
+            for attempt in range(5):
+                try:
+                    os.replace(tmp_path, target)
+                    break
+                except PermissionError:
+                    if attempt == 4:
+                        raise
+                    time.sleep(0.01 * (2**attempt))
         except BaseException:
             with contextlib.suppress(FileNotFoundError):
                 tmp_path.unlink()