project: Spawn terminal process on background executor (#40774)

We were spawning the process on the foreground thread before which can
block an arbitrary amount of time. Likewise we no longer block
deserialization on the terminal loading.

Release Notes:

- Improved startup time on systems with slow process spawning
capabilities
0eccdfe61fLukas Wirth committed on 10/21/2025, 1:10:21 PM· committed by GitHubparent0be70e2
28 files changedLine totals unavailable