refactor(polyfills): do not raise a Assignment call unless needed. (#242)

* Update polyfills.ts

Signed-off-by: Reaper Gelera <ahoy@barelyhuman.dev>

* chore: style fix

---------

Signed-off-by: Reaper Gelera <ahoy@barelyhuman.dev>

Author: barelyhuman

lib/polyfills.ts

@@ -46,5 +46,7 @@ const ArrayConstructors = [
 ];
 
 ArrayConstructors.forEach((ArrayConstructor) => {
-  ArrayConstructor.prototype.at = ArrayConstructor.prototype.at ?? at;
+  if (!Object.prototype.hasOwnProperty.call(ArrayConstructor, 'at')) {
+    ArrayConstructor.prototype.at = at;
+  }
 });