`readline.set_history_length` results in unreadable history files

Hello,
Writing a history file after a call to `readline.set_history_length` results in an unreadable history file. For example, with `cpython-3.12.4+20240713-x86_64-unknown-linux-gnu-install_only.tar.gz`:
```py
import readline
import os

readline.add_history("first line")
readline.add_history("second line")
readline.add_history("third line")

readline.set_history_length(2)
readline.write_history_file('historyfile.tmp')
try:
readline.read_history_file('historyfile.tmp')
finally:
os.remove('historyfile.tmp')
```
gives me a traceback on the `read_history_file`:
```
Traceback (most recent call last):
File "/script.py", line 12, in
readline.read_history_file('historyfile.tmp')
OSError: [Errno 22] Invalid argument
```

This might be a conflict/incompatibility between editline and a history library that doesn't work with editline's `_HiStOrY_V2_` format.

I've [added a test to CPython](https://github.com/python/cpython/pull/121326) that should fail in this case. I don't know what more I can do on the CPython side.

The same “Invalid argument” error happens when trying to read a history file produced with GNU readline. This can affect users switching from some earlier standalone builds.

Run the Python reproduction in the issue and compare history files produced after readline.set_history_length with files from GNU readline and editline. Review the linked CPython test pull request for the expected round-trip behavior; done means the standalone build can write and read the affected history files without OSError.

Written by the indexing model from the issue text.