zed: Add timeouts for feature flag resolution in workspace panel initialization (#22715)

This PR adds timeouts when resolving feature flags during workspace
panel initialization so that we don't block indefinitely if Zed is not
connected to the internet.

Right now we wait for 5 seconds, but this value was chosen arbitrarily.

Release Notes:

- N/A

crates/zed/src/zed.rs

@@ -20,6 +20,7 @@ use command_palette_hooks::CommandPaletteFilter;
 use editor::ProposedChangesEditorToolbar;
 use editor::{scroll::Autoscroll, Editor, MultiBuffer};
 use feature_flags::FeatureFlagAppExt;
+use futures::FutureExt;
 use futures::{channel::mpsc, select_biased, StreamExt};
 use gpui::{
     actions, point, px, AppContext, AsyncAppContext, Context, FocusableView, MenuItem,
@@ -348,7 +349,16 @@ fn initialize_panels(prompt_builder: Arc<PromptBuilder>, cx: &mut ViewContext<Wo
             workspace.add_panel(assistant_panel, cx)
         })?;
 
-        let git_ui_enabled = git_ui_feature_flag.await;
+        let git_ui_enabled = {
+            let mut git_ui_feature_flag = git_ui_feature_flag.fuse();
+            let mut timeout =
+                FutureExt::fuse(smol::Timer::after(std::time::Duration::from_secs(5)));
+
+            select_biased! {
+                is_git_ui_enabled = git_ui_feature_flag => is_git_ui_enabled,
+                _ = timeout => false,
+            }
+        };
         let git_panel = if git_ui_enabled {
             Some(git_ui::git_panel::GitPanel::load(workspace_handle.clone(), cx.clone()).await?)
         } else {
@@ -363,7 +373,14 @@ fn initialize_panels(prompt_builder: Arc<PromptBuilder>, cx: &mut ViewContext<Wo
         let is_assistant2_enabled = if cfg!(test) {
             false
         } else {
-            assistant2_feature_flag.await
+            let mut assistant2_feature_flag = assistant2_feature_flag.fuse();
+            let mut timeout =
+                FutureExt::fuse(smol::Timer::after(std::time::Duration::from_secs(5)));
+
+            select_biased! {
+                is_assistant2_enabled = assistant2_feature_flag => is_assistant2_enabled,
+                _ = timeout => false,
+            }
         };
         let assistant2_panel = if is_assistant2_enabled {
             Some(assistant2::AssistantPanel::load(workspace_handle.clone(), cx.clone()).await?)