linux: Hide Install CLI from welcome (#14506)

Release Notes:

- linux: Remove "Install CLI" from welcome, it is not necessary

crates/welcome/src/welcome.rs

@@ -123,7 +123,8 @@ impl Render for WelcomePage {
                                             .ok();
                                     })),
                             )
-                            .child(
+                            .when(cfg!(target_os = "macos"), |el| {
+                                el.child(
                                     Button::new("install-cli", "Install the CLI")
                                         .full_width()
                                         .on_click(cx.listener(|this, _, cx| {
@@ -137,6 +138,7 @@ impl Render for WelcomePage {
                                                 .detach_and_log_err(cx);
                                         })),
                                 )
+                            })
                             .child(
                                 Button::new("sign-in-to-copilot", "Sign in to GitHub Copilot")
                                     .full_width()