fix: explicitly list dependencies in "workspaces+sway" feature

Co-authored-by: Jake Stanger <mail@jstanger.dev>

Cargo.toml

@@ -73,7 +73,7 @@ volume = ["libpulse-binding"]
 
 workspaces = ["futures-lite"]
 "workspaces+all" = ["workspaces", "workspaces+sway", "workspaces+hyprland"]
-"workspaces+sway" = ["workspaces", "sway"]
+"workspaces+sway" = ["workspaces", "swayipc-async"]
 "workspaces+hyprland" = ["workspaces", "hyprland"]
 
 sway = ["swayipc-async"]