[fuzz] Pre-existing Python front-end bug (seed 1777979839)

[github-actions]

A fuzz test found a pre-existing failure in the Python front-end.

Seed: 1777979839
PR: #984
Merge base also fails: yes

Generated program

def main():
    assert isinstance(True, bool), "isinstance bool"

    d: dict = {'b': -13, 'd': 9}
    assert d['b'] == -13, "dict access"

    assert 'foobar'[2] == 'o', "str index"

main()

Reproduce

cd Tools/Python
./scripts/hypothesmith.sh 10 1777979839 both --unrestricted

This bug exists on main and was not introduced by the PR.