call: Update call location when active multi workspace changes (#52441)

## Context

This fixes a participant location out of sync bug when the active
workspace changes in a multi workspace. It wouldn't update the project
id, which breaks following.

## Self-Review Checklist

<!-- Check before requesting review: -->
- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Release Notes:

- N/A

crates/call/src/call_impl/mod.rs

@@ -17,8 +17,8 @@ use room::Event;
 use settings::Settings;
 use std::sync::Arc;
 use workspace::{
-    ActiveCallEvent, AnyActiveCall, GlobalAnyActiveCall, Pane, RemoteCollaborator, SharedScreen,
-    Workspace,
+    ActiveCallEvent, AnyActiveCall, GlobalAnyActiveCall, MultiWorkspace, MultiWorkspaceEvent, Pane,
+    RemoteCollaborator, SharedScreen, Workspace,
 };
 
 pub use livekit_client::{RemoteVideoTrack, RemoteVideoTrackView, RemoteVideoTrackViewEvent};
@@ -28,6 +28,36 @@ use crate::call_settings::CallSettings;
 
 pub fn init(client: Arc<Client>, user_store: Entity<UserStore>, cx: &mut App) {
     let active_call = cx.new(|cx| ActiveCall::new(client, user_store, cx));
+    let active_call_handle = active_call.downgrade();
+
+    cx.observe_new(move |_multi_workspace: &mut MultiWorkspace, window, cx| {
+        let Some(window) = window else {
+            return;
+        };
+
+        let active_call_handle = active_call_handle.clone();
+        cx.subscribe_in(
+            &cx.entity(),
+            window,
+            move |multi_workspace, _, event: &MultiWorkspaceEvent, window, cx| {
+                if !matches!(event, MultiWorkspaceEvent::ActiveWorkspaceChanged)
+                    && window.is_window_active()
+                {
+                    return;
+                }
+
+                let project = multi_workspace.workspace().read(cx).project().clone();
+                if let Ok(task) = active_call_handle.update(cx, |active_call, cx| {
+                    active_call.set_location(Some(&project), cx)
+                }) {
+                    task.detach_and_log_err(cx);
+                }
+            },
+        )
+        .detach();
+    })
+    .detach();
+
     cx.set_global(GlobalAnyActiveCall(Arc::new(ActiveCallEntity(active_call))))
 }