Use read-only access methods for read-only entity operations (#31479)

Another follow-up to #31254

Release Notes:

- N/A

crates/project/src/task_store.rs

@@ -70,7 +70,7 @@ impl TaskStore {
             .payload
             .location
             .context("no location given for task context handling")?;
-        let (buffer_store, is_remote) = store.update(&mut cx, |store, _| {
+        let (buffer_store, is_remote) = store.read_with(&mut cx, |store, _| {
             Ok(match store {
                 TaskStore::Functional(state) => (
                     state.buffer_store.clone(),