I don't think this is quite correct. The same error occurs in my Python 3.10 venv on an M2 Max MBP running Sonoma 14.6.1, using packages tensorflow==2.20.0 and tensorflow-metal==1.2.0. Something is truly broken here.

Not quite so. The same error occurs for me using tensorflow==2.20.0 and tensorflow-metal==1.2.0 in a Python 3.10 venv running on an M2 Max MBP.