chore: address clippy concern for readability

src/heat_seek.rs

@@ -249,7 +249,7 @@ async fn map_heat(
             let mut changed = false;
             for (&channel, &heat) in &*channel_heat_watcher.borrow() {
                 let existing = heat_map.insert(heat, channel);
-                if existing.map_or(true, |(old_heat, old_channel)| {
+                if existing.is_none_or(|(old_heat, old_channel)| {
                     old_heat != heat || channel != old_channel
                 }) {
                     changed = true;