Where there's an f-string that has a debug expression in the last line of a file, the debug expression buffer is one character too short. For example:

```python3 cpython on  main via C v14.0.3-clang via 🐍 pyenv 3.11.3 took 15s ❯ cat tmp/t.py print(f'''{ 3 =}''')% cpython on  main via C v14.0.3-clang via 🐍 pyenv 3.11.3 ❯ ./python.exe tmp/t.py 3 3

A fix is already up as part of gh-105828, so just opening this to track the issue.

Linked PRs

• gh-105831: Fix NEWS blurb from gh-105828 #105833