Bail and signal error when the cwd of a resolved task doesn't exist (#32777)

Closes #32688

Release Notes:

- Fixed tasks (including build tasks for debug configurations) silently
using `/` as a working directory when the specified `cwd` didn't exist.

crates/workspace/src/workspace.rs

@@ -135,7 +135,7 @@ pub trait TerminalProvider {
         &self,
         task: SpawnInTerminal,
         window: &mut Window,
-        cx: &mut App,
+        cx: &mut Context<Workspace>,
     ) -> Task<Option<Result<ExitStatus>>>;
 }