Fix const list for python 2.7

[wangym5106]

Example:

a = ['a', 'b', 'c', 'd', 'e']

Decompiled result:

# uncompyle6 version 3.9.3
# Python bytecode version base 2.7 (62211)
# Decompiled from: Python 3.12.10 (tags/v3.12.10:0cc8128, Apr  8 2025, 12:21:36) [MSC v.1943 64 bit (AMD64)]     
# Embedded file name: /cwd/test.py
# Compiled at: 2025-11-21 19:04:42
a = [
 0, 1, 2, 3, 4]

The issue seems caused by 8a1fd7e and 9fd139a , removed logic for Python 2
This PR recovers the logic and fix the issue