Remove edit action markers from `edit_prompt.md` (#27785)

https://github.com/zed-industries/zed/pull/27778 removed most
occurrences, but there were still some more in `edit_prompt.md`

Release Notes:

- N/A
d40b49ceb9Agus Zubiaga committed on 3/31/2025, 5:49:40 PM· committed by GitHubparentedf712d
3 files changedLine totals unavailable