Fix clippy warnings

Author: pierrechevalier83

src/main.rs

@@ -72,7 +72,7 @@ fn pretty_windows(config: &Config, windows: &[Window]) -> String {
         let mut set = HashSet::new();
         for window in windows {
             let icon = pretty_window(config, window);
-            if set.get(&icon).is_none() {
+            if !set.contains(&icon) {
                 s.push_str(&icon);
                 s.push(' ');
                 set.insert(icon);

src/window_manager.rs

@@ -313,7 +313,7 @@ impl WM for SwayOrI3 {
         }
         for result in self
             .connection
-            .run_command(&format!("rename workspace \"{old}\" to \"{new}\"",))
+            .run_command(format!("rename workspace \"{old}\" to \"{new}\"",))
             .context("Failed to rename the workspace")?
         {
             result.context("Failed to rename the workspace")?;