Use read-only access methods for read-only entity operations (#31254)

This PR replaces some `update()` calls with either `read()` or
`read_with()` when the `update()` call performed read-only operations on
the entity.

Many more likely exist, will follow-up with more PRs.

Release Notes:

- N/A

crates/debugger_ui/src/tests/console.rs

@@ -33,7 +33,7 @@ async fn test_handle_output_event(executor: BackgroundExecutor, cx: &mut TestApp
         .unwrap();
 
     let session = start_debug_session(&workspace, cx, |_| {}).unwrap();
-    let client = session.update(cx, |session, _| session.adapter_client().unwrap());
+    let client = session.read_with(cx, |session, _| session.adapter_client().unwrap());
 
     client.on_request::<StackTrace, _>(move |_, _| {
         Ok(dap::StackTraceResponse {

crates/debugger_ui/src/tests/debugger_panel.rs

@@ -1015,7 +1015,7 @@ async fn test_debug_panel_item_thread_status_reset_on_failure(
     cx.run_until_parked();
 
     let running_state = active_debug_session_panel(workspace, cx)
-        .update(cx, |item, _| item.running_state().clone());
+        .read_with(cx, |item, _| item.running_state().clone());
 
     cx.run_until_parked();
     let thread_id = ThreadId(1);