terminal: Do not auto close shell terminals if they error out (#38182)

Closes https://github.com/zed-industries/zed/issues/38134

This also reduces an annoying level of shell nesting

Release Notes:

- N/A

crates/remote/src/remote_client.rs

@@ -769,13 +769,11 @@ impl RemoteClient {
     }
 
     pub fn shell(&self) -> Option<String> {
-        Some(self.state.as_ref()?.remote_connection()?.shell())
+        Some(self.remote_connection()?.shell())
     }
 
     pub fn shares_network_interface(&self) -> bool {
-        self.state
-            .as_ref()
-            .and_then(|state| state.remote_connection())
+        self.remote_connection()
             .map_or(false, |connection| connection.shares_network_interface())
     }
 
@@ -787,12 +785,8 @@ impl RemoteClient {
         working_dir: Option<String>,
         port_forward: Option<(u16, String, u16)>,
     ) -> Result<CommandTemplate> {
-        let Some(connection) = self
-            .state
-            .as_ref()
-            .and_then(|state| state.remote_connection())
-        else {
-            return Err(anyhow!("no connection"));
+        let Some(connection) = self.remote_connection() else {
+            return Err(anyhow!("no ssh connection"));
         };
         connection.build_command(program, args, env, working_dir, port_forward)
     }
@@ -803,11 +797,7 @@ impl RemoteClient {
         dest_path: RemotePathBuf,
         cx: &App,
     ) -> Task<Result<()>> {
-        let Some(connection) = self
-            .state
-            .as_ref()
-            .and_then(|state| state.remote_connection())
-        else {
+        let Some(connection) = self.remote_connection() else {
             return Task::ready(Err(anyhow!("no ssh connection")));
         };
         connection.upload_directory(src_path, dest_path, cx)
@@ -916,6 +906,12 @@ impl RemoteClient {
             .unwrap()
             .unwrap()
     }
+
+    fn remote_connection(&self) -> Option<Arc<dyn RemoteConnection>> {
+        self.state
+            .as_ref()
+            .and_then(|state| state.remote_connection())
+    }
 }
 
 enum ConnectionPoolEntry {