Update on "mkdir when destination directory doesn't exist"

Fixes #8980

Make sure we mkdir if destination directory doesn't exist. I have no
idea why it doesn't work before

cc lucylq

[ghstack-poisoned]

Author: larryliu0820

setup.py

@@ -464,10 +464,8 @@ def build_extension(self, ext: _BaseExtension) -> None:
 
         # Ensure that the destination directory exists.
         if not dst_file.parent.exists():
-            print(f"DEBUG 1: dest parent directory {dst_file.parent}, exists? {dst_file.parent.exists()}")
             self.mkpath(os.fspath(dst_file.parent))
-            print(f"DEBUG 2: dest parent directory {dst_file.parent}, exists? {dst_file.parent.exists()}")
-            
+
         # Copy the file.
         self.copy_file(os.fspath(src_file), os.fspath(dst_file))