gpui_tokio: Fix `child task panicked: JoinError::Cancelled` panics (#51995)

This panic stemmed from us dropping the tokio runtime before dropping
wasm tasks which then could attempt to spawn_blocking, immediately
failing and panicking on unwrap inside wasmtime.

Closes ZED-5DE

Release Notes:

- N/A or Added/Fixed/Improved ...
283bab5bf1Lukas Wirth committed on 3/20/2026, 8:46:54 AM· committed by GitHubparent2839676
2 files changedLine totals unavailable