Fix runnables-related hickups (#8058)

* never error on absent/empty runnables file
* always activate terminal tab on runnable (re)schedule

Release Notes:

- N/A
48a6fb9e84Kirill Bulatov committed on 2/20/2024, 12:54:19 PM· committed by GitHubparente9f400a
2 files changedLine totals unavailable