Fix auth in edit_agent evals (#37869)

Somehow we have a regression where the auth wasn't being called, so the
model didn't exist.

Looking at the code, it is likely this was relying on some other part of
the code doing the auth, since the order wouldn't have worked before
without that happening. This new order of doing auth before checking for
available models should fix it going forward.

Release Notes:

- N/A

crates/assistant_tools/src/edit_agent/evals.rs

@@ -1520,7 +1520,15 @@ impl EditAgentTest {
         selected_model: &SelectedModel,
         cx: &mut AsyncApp,
     ) -> Result<Arc<dyn LanguageModel>> {
-        let (provider, model) = cx.update(|cx| {
+        cx.update(|cx| {
+            let registry = LanguageModelRegistry::read_global(cx);
+            let provider = registry
+                .provider(&selected_model.provider)
+                .expect("Provider not found");
+            provider.authenticate(cx)
+        })?
+        .await?;
+        cx.update(|cx| {
             let models = LanguageModelRegistry::read_global(cx);
             let model = models
                 .available_models(cx)
@@ -1529,11 +1537,8 @@ impl EditAgentTest {
                         && model.id() == selected_model.model
                 })
                 .expect("Model not found");
-            let provider = models.provider(&model.provider_id()).unwrap();
-            (provider, model)
-        })?;
-        cx.update(|cx| provider.authenticate(cx))?.await?;
-        Ok(model)
+            model
+        })
     }
 
     async fn eval(&self, eval: EvalInput, cx: &mut TestAppContext) -> Result<EvalOutput> {