During Phase 3d it surfaced that several widgets keep a three-clause
cfg `#[cfg(all(feature = "winit", feature = "wayland", target_os = "linux"))]`
(e.g. dropdown::widget::with_popup, widget/mod.rs menu bits,
theme/style/mod.rs). Since the yoda fork is wayland-only the "winit"
clause is vestigial — dropping it unhides these methods for Wayland
consumers (cosmic-settings needs Dropdown::with_popup on the wallpaper
page).
Also fixed a cfg asymmetry in responsive_menu_bar.rs: the fallback
block was gated `cfg(not(all(winit, wayland, linux)))` while the
primary block was `cfg(all(wayland, linux))`. With winit removed both
blocks were active and we got E0308 expected-() — aligned the cfgs so
exactly one branch compiles.
