gh-149321: Fix stdlib imports with lazy imports disabled

[pablogsal]

• Issue: What is supposed to work under -X lazy_imports=none? #149321

[danielhollas]

I am surprised that this is needed. Up until very recently, inspect was imported eagerly in dataclasses. Isn't the issue with importing dataclasses fixed by the ast change alone?

[pablogsal]

IIRC the ast change fixes one cycle, but not all of them. If I restore the top-level lazy import inspect in dataclasses, import dataclasses still fails under -X azy_imports=none via: dataclasses -> inspect -> tokenize -> _colorize -> dataclasses

So the inspect move is specifically about avoiding import-time resolution of the lazy inspect import when lazy imports are disabled. The failure is reproducible with a direct import dataclasses, and the stdlib import subprocess test catches it as well.