assistant edit tool: Do not include `\r` in old/new str (#26542)

#26538 fixed part of the issue, but it would keep trailing carriage
returns in the old/new strings. The model is unlikely to produce those,
but we might as well support them.

Release Notes:

- N/A
669c6a3d5eAgus Zubiaga committed on 3/12/2025, 2:34:40 PM· committed by GitHubparent910531b
1 file changedLine totals unavailable