Suppress a backtrace in extension error logging (#43917)

One less redundant backtrace in the logs:

<img width="2032" height="1161" alt="backtrace"
src="https://github.com/user-attachments/assets/f03192b4-1b9c-4fa1-809d-9e826452f711"
/>

Release Notes:

- N/A

crates/extension_host/src/headless_host.rs

@@ -96,7 +96,7 @@ impl HeadlessExtensionStore {
 
             for extension in to_load {
                 if let Err(e) = Self::load_extension(this.clone(), extension.clone(), cx).await {
-                    log::info!("failed to load extension: {}, {:?}", extension.id, e);
+                    log::info!("failed to load extension: {}, {:#}", extension.id, e);
                     missing.push(extension)
                 } else if extension.dev {
                     missing.push(extension)