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/agent/src/context_picker/completion_provider.rs

@@ -1213,7 +1213,7 @@ mod tests {
             assert_eq!(worktrees.len(), 1);
             worktrees.pop().unwrap()
         });
-        let worktree_id = worktree.update(cx, |worktree, _| worktree.id());
+        let worktree_id = worktree.read_with(cx, |worktree, _| worktree.id());
 
         let mut cx = VisualTestContext::from_window(*window.deref(), cx);
 

crates/agent/src/inline_prompt_editor.rs

@@ -326,9 +326,7 @@ impl<T: 'static> PromptEditor<T> {
             EditorEvent::Edited { .. } => {
                 if let Some(workspace) = window.root::<Workspace>().flatten() {
                     workspace.update(cx, |workspace, cx| {
-                        let is_via_ssh = workspace
-                            .project()
-                            .update(cx, |project, _| project.is_via_ssh());
+                        let is_via_ssh = workspace.project().read(cx).is_via_ssh();
 
                         workspace
                             .client()

crates/agent/src/thread.rs

@@ -2851,7 +2851,8 @@ mod tests {
             .await
             .unwrap();
 
-        let context = context_store.update(cx, |store, _| store.context().next().cloned().unwrap());
+        let context =
+            context_store.read_with(cx, |store, _| store.context().next().cloned().unwrap());
         let loaded_context = cx
             .update(|cx| load_context(vec![context], &project, &None, cx))
             .await;
@@ -3162,7 +3163,8 @@ fn main() {{
             .await
             .unwrap();
 
-        let context = context_store.update(cx, |store, _| store.context().next().cloned().unwrap());
+        let context =
+            context_store.read_with(cx, |store, _| store.context().next().cloned().unwrap());
         let loaded_context = cx
             .update(|cx| load_context(vec![context], &project, &None, cx))
             .await;