Hide the implementation of Task (#22009)

The `Option<T>` within `Ready` is confusing and using `None` for it can
cause crashes. There was actually one instance of this!

Release Notes:

- N/A

crates/workspace/src/workspace.rs

@@ -1651,7 +1651,7 @@ impl Workspace {
         F: 'static + FnOnce(&mut Workspace, &mut ViewContext<Workspace>) -> T,
     {
         if self.project.read(cx).is_local() {
-            Task::Ready(Some(Ok(callback(self, cx))))
+            Task::ready(Ok(callback(self, cx)))
         } else {
             let env = self.project.read(cx).cli_environment(cx);
             let task = Self::new_local(Vec::new(), self.app_state.clone(), None, env, cx);