Use regular info color for speaker borders (#4126)

This PR updates the speaker borders to use the regular `info` status
color instead of the `info_border` color.

This should provide more contrast and make it clearer as to who is
speaking.

Release Notes:

- Made the active speakers' borders more visible when in a call.

crates/collab_ui/src/collab_titlebar_item.rs

@@ -486,7 +486,7 @@ impl CollabTitlebarItem {
                 Avatar::new(user.avatar_uri.clone())
                     .grayscale(!is_present)
                     .border_color(if is_speaking {
-                        cx.theme().status().info_border
+                        cx.theme().status().info
                     } else {
                         // We draw the border in a transparent color rather to avoid
                         // the layout shift that would come with adding/removing the border.