Update http link to https in onboarding_modal.rs (#39135)

Use https protocol

Closes #ISSUE

Release Notes:

- N/A *or* Added/Fixed/Improved ...

crates/agent_ui/src/ui/onboarding_modal.rs

@@ -40,7 +40,7 @@ impl AgentOnboardingModal {
     }
 
     fn view_blog(&mut self, _: &ClickEvent, _: &mut Window, cx: &mut Context<Self>) {
-        cx.open_url("http://zed.dev/blog/fastest-ai-code-editor");
+        cx.open_url("https://zed.dev/blog/fastest-ai-code-editor");
         cx.notify();
 
         agent_onboarding_event!("Blog Link Clicked");