fix Pyrefly infers Iterator[Any] instead of Iterator[int] for iter([0]) #3265

[asukaminato0721]

Summary

Fixes #3265

Prevented bounded generic Any from incorrectly contextually typing list literals.

Test Plan

add test

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

cki-lib (https://gitlab.com/cki-project/cki-lib)
- ERROR cki_lib/metrics/server.py:23:12-24: Returned type `Iterator[Any]` is not assignable to declared return type `None` [bad-return]
+ ERROR cki_lib/metrics/server.py:23:12-24: Returned type `Iterator[Unknown]` is not assignable to declared return type `None` [bad-return]