Apply suggestions from code review

Co-authored-by: Steven <steven@ceriously.com>

src/index.ts

@@ -59,7 +59,7 @@ async function main() {
 
       let cancel_before;
       if (all_but_latest) {
-        cancel_before = new Date(data.workflow_runs.reduce((a, b) => a.created_at < b.created_at ? a.created_at : b.created_at));
+        cancel_before = new Date(data.workflow_runs.reduce((a, b) => Math.min(a.created_at, b.created_at);
       } else {
         cancel_before = new Date(current_run.created_at);
       }