Optimize REPL kernel spec refresh (#21844)

Python kernelspec refresh now only performed on (known) python files. 

Release Notes:

- N/A

crates/repl/src/repl_sessions_ui.rs

@@ -73,14 +73,18 @@ pub fn init(cx: &mut AppContext) {
                 return;
             }
 
-            let project_path = editor
+            let buffer = editor.buffer().read(cx).as_singleton();
-                .buffer()
+
-                .read(cx)
+            let language = buffer
-                .as_singleton()
+                .as_ref()
-                .and_then(|buffer| buffer.read(cx).project_path(cx));
+                .and_then(|buffer| buffer.read(cx).language());
+
+            let project_path = buffer.and_then(|buffer| buffer.read(cx).project_path(cx));
 
             let editor_handle = cx.view().downgrade();
 
+            if let Some(language) = language {
+                if language.name() == "Python".into() {
                     if let (Some(project_path), Some(project)) = (project_path, project) {
                         let store = ReplStore::global(cx);
                         store.update(cx, |store, cx| {
@@ -89,6 +93,8 @@ pub fn init(cx: &mut AppContext) {
                                 .detach_and_log_err(cx);
                         });
                     }
+                }
+            }
 
             editor
                 .register_action({

crates/repl/src/repl_store.rs

@@ -173,7 +173,7 @@ impl ReplStore {
 
         let remote_kernel_specifications = self.get_remote_kernel_specifications(cx);
 
-        cx.spawn(|this, mut cx| async move {
+        let all_specs = cx.background_executor().spawn(async move {
             let mut all_specs = local_kernel_specifications
                 .await?
                 .into_iter()
@@ -186,10 +186,21 @@ impl ReplStore {
                 }
             }
 
+            anyhow::Ok(all_specs)
+        });
+
+        cx.spawn(|this, mut cx| async move {
+            let all_specs = all_specs.await;
+
+            if let Ok(specs) = all_specs {
                 this.update(&mut cx, |this, cx| {
-                this.kernel_specifications = all_specs;
+                    this.kernel_specifications = specs;
                     cx.notify();
                 })
+                .ok();
+            }
+
+            anyhow::Ok(())
         })
     }