Use Tokio::spawn instead of getting an executor handle (#36701)

This was causing panics due to the handles being dropped out of order.
It doesn't seem possible to guarantee the correct drop ordering given
that we're holding them over await points, so lets just spawn on the
tokio executor itself which gives us access to the state we needed those
handles for in the first place.

Fixes: ZED-1R

Release Notes:

- N/A

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>
Co-authored-by: Marshall Bowers <git@maxdeviant.com>

crates/cloud_api_client/src/cloud_api_client.rs

@@ -102,13 +102,7 @@ impl CloudApiClient {
         let credentials = credentials.as_ref().context("no credentials provided")?;
         let authorization_header = format!("{} {}", credentials.user_id, credentials.access_token);
 
-        Ok(cx.spawn(async move |cx| {
-            let handle = cx
-                .update(|cx| Tokio::handle(cx))
-                .ok()
-                .context("failed to get Tokio handle")?;
-            let _guard = handle.enter();
-
+        Ok(Tokio::spawn_result(cx, async move {
             let ws = WebSocket::connect(connect_url)
                 .with_request(
                     request::Builder::new()