Follow-up of https://github.com/zed-industries/zed/pull/28993
* Tone down tasks' cancellation logging
* Fix task terminals' leak, disallowing to fully cancel the task by
dropping the terminal off the pane:
f619d5f02a/crates/terminal_view/src/terminal_panel.rs (L1464-L1471)
Release Notes:
- Fixed tasks not being stopped on reruns