remove file writing in metal ops (tinygrad#2369)

* remove file writing in metal ops

* remove unused import

---------

Co-authored-by: ductm104 <ductm>

tinygrad/runtime/ops_metal.py

@@ -1,6 +1,6 @@
 # pip3 install pyobjc-framework-Metal pyobjc-framework-Cocoa pyobjc-framework-libdispatch
 import os, subprocess, pathlib, ctypes, tempfile
-import Metal, Cocoa, libdispatch
+import Metal, libdispatch
 from typing import List, Any, Tuple, Dict, Union, Set, cast
 from tinygrad.codegen.kernel import LinearizerOptions
 from tinygrad.helpers import prod, getenv, DEBUG, DType, dtypes, diskcache, dedup
@@ -53,10 +53,7 @@ def compile_metal(prg, use_xcode=bool(getenv("METAL_XCODE"))) -> bytes:
  return subprocess.check_output(['xcrun', '-sdk', 'macosx', 'metallib', '-', '-o', '-'], input=air)
  options = Metal.MTLCompileOptions.new()
  library = unwrap(METAL.device.newLibraryWithSource_options_error_(prg, options, None))
- # TODO: avoid file write here?
- with tempfile.NamedTemporaryFile(delete=True) as output_file:
- unwrap(library.serializeToURL_error_(Cocoa.NSURL.URLWithString_(f"file:https://{output_file.name}"), None))
- return pathlib.Path(output_file.name).read_bytes()
+ return library.libraryDataContents().bytes().tobytes()
 
 class MetalProgram:
  def __init__(self, name:str, lib:bytes):