fix: change const to let

Signed-off-by: Slowlife <slowlife1165@gmail.com>

src/browser/base/zen-components/ZenTabUnloader.mjs

@@ -209,7 +209,7 @@
       // Please note that calling sort on an array will modify that array.
       // you might want to clone your array first.
 
-      for (const i = 0; i < a.length; ++i) {
+      for (let i = 0; i < a.length; ++i) {
         if (a[i] !== b[i]) return false;
       }
       return true;