agent: Fix profiles tooltip border (#46396)

One _character_ change to fix the dividing border in the agent panel's
profile tooltip. 😬

Release Notes:

- N/A

crates/agent_ui/src/profile_selector.rs

@@ -196,8 +196,8 @@ impl Render for ProfileSelector {
                         ))
                         .child(
                             container()
-                                .pb_1()
-                                .border_b_1()
+                                .pt_1()
+                                .border_t_1()
                                 .border_color(cx.theme().colors().border_variant)
                                 .child(Label::new("Cycle Through Profiles"))
                                 .child(KeyBinding::for_action_in(