LibJS: Make define_property always throw if specified

Now put uses is_strict_mode to determine define_property should throw

Userland/Libraries/LibJS/Tests/builtins/Array/Array.prototype.shift.js

@@ -26,7 +26,7 @@ test("Issue #5884, GenericIndexedPropertyStorage::take_first() loses elements",
     const a = [];
     for (let i = 0; i < 300; i++) {
         // NOTE: We use defineProperty to prevent the array from using SimpleIndexedPropertyStorage
-        Object.defineProperty(a, i, { value: i, writable: false });
+        Object.defineProperty(a, i, { value: i, configurable: true });
     }
     expect(a.length).toBe(300);
     for (let i = 0; i < 300; i++) {