python3: fix a regression

[tornaria]

Issue: python/cpython#135326
PR: python/cpython#135332

Testing the changes

• I tested the changes in this PR: briefly

@ahesford

The regression causes problems in sagemath, e.g.:

$ sage
┌────────────────────────────────────────────────────────────────────┐
│ SageMath version 10.6, Release Date: 2025-03-31                    │
│ Using Python 3.13.4. Type "help()" for help.                       │
└────────────────────────────────────────────────────────────────────┘
sage: import random ; r = random.Random()
sage: r.getrandbits(20)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
...
TypeError: an integer is required