Make closing the SSH modal equivalent to cancelling the SSH connection task (#19568)

TODO: 
- [x] Fix focus not being on the modal initially

Release Notes:

- N/A

---------

Co-authored-by: Trace <violet.white.batt@gmail.com>

crates/workspace/src/workspace.rs

@@ -5534,6 +5534,7 @@ pub fn join_hosted_project(
 pub fn open_ssh_project(
     window: WindowHandle<Workspace>,
     connection_options: SshConnectionOptions,
+    cancel_rx: oneshot::Receiver<()>,
     delegate: Arc<dyn SshClientDelegate>,
     app_state: Arc<AppState>,
     paths: Vec<PathBuf>,
@@ -5555,11 +5556,21 @@ pub fn open_ssh_project(
             workspace_id.0
         );
 
-        let session = cx
+        let session = match cx
             .update(|cx| {
-                remote::SshRemoteClient::new(unique_identifier, connection_options, delegate, cx)
+                remote::SshRemoteClient::new(
+                    unique_identifier,
+                    connection_options,
+                    cancel_rx,
+                    delegate,
+                    cx,
+                )
             })?
-            .await?;
+            .await?
+        {
+            Some(result) => result,
+            None => return Ok(()),
+        };
 
         let project = cx.update(|cx| {
             project::Project::ssh(