PKG: exclude psychtoolbox on arm64 chips

It does now install a wheel but then fails to load with

```
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/psychtoolbox/__init__.py", line 31, in <module>
    from .PsychPortAudio import PsychPortAudio
ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/psychtoolbox/PsychPortAudio.cpython-310-darwin.so, 0x0002): symbol not found in flat namespace '_PaMacCore_GetBufferSizeRange'
```

pyproject.toml

@@ -40,7 +40,7 @@ dependencies = [
     "soundfile",
     "imageio",
     "imageio-ffmpeg",
-    "psychtoolbox",
+    "psychtoolbox; platform_machine!='arm64'",
     # for iohub
     "pywinhook; platform_system == \"Windows\"",
     "gevent",