[Process] clarify idle timeout
minor #10097 [Process] clarify idle timeout (Tobion)

This PR was merged into the 2.4 branch.

Discussion
----------

[Process] clarify idle timeout

| Q             | A
| ------------- | ---
| Bug fix?      | sort of
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | n/a

Makes idle timeout in line with #9466

Commits
-------

9f07b4d [Process] clarify idle timeout