sys.setrecursionlimit no longer affecting pickle.dump

Bug report

Bug description:

This is a follow up of https://github.com/python/cpython/issues/112282 (updating doc).
It's also a different case of https://github.com/python/cpython/issues/128544 (import chains impacted).

In particular, on top of the doc no longer being correct for sys.setrecursionlimit, the regression needs to be fixed.

Note: this works in python 3.11 or below.

import pickle
import sys

nested_object = current = {}
for i in range(10000):
    current['nested'] = {}
    current = current['nested']

sys.setrecursionlimit(3750000)
x = pickle.dumps(nested_object)

Result of the run:

▶▶ python3.11 test-issue.py
# runs ok

▶▶ python3.12 test-issue.py
Traceback (most recent call last):
  File "~/test-issue.py", line 10, in <module>
    x = pickle.dumps(nested_object)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^
RecursionError: maximum recursion depth exceeded while pickling an object

Impact: all programs trying to pickle data that is too nested cannot be ported to python 3.12 or 3.13 so far

CPython versions tested on:

3.12, 3.13

Operating systems tested on:

Linux, macOS, Windows

Run the provided nested-dictionary reproducer under Python 3.11 and 3.12, then trace how pickle.dumps handles recursion after sys.setrecursionlimit is raised. The fix is complete when the example succeeds on the affected versions without the RecursionError, while preserving the documented recursion-limit behavior.