fix increasing .size in URLSearchParams.prototype.append polyfill in IE8-

Author: zloirock

CHANGELOG.md

@@ -1,5 +1,6 @@
 # Changelog
 ### Unreleased
+- Fixed increasing `.size` in `URLSearchParams.prototype.append` polyfill in IE8-
 - Compat data improvements:
   - Missed [Explicit Resource Management](https://github.com/tc39/proposal-explicit-resource-management) features [added in Bun 1.3.0](https://bun.com/blog/bun-v1.3#disposablestack-and-asyncdisposablestack)
 

packages/core-js/modules/web.url-search-params.constructor.js

@@ -313,7 +313,7 @@ defineBuiltIns(URLSearchParamsPrototype, {
     var state = getInternalParamsState(this);
     validateArgumentsLength(arguments.length, 2);
     push(state.entries, { key: $toString(name), value: $toString(value) });
-    if (!DESCRIPTORS) this.length++;
+    if (!DESCRIPTORS) this.size++;
     state.updateURL();
   },
   // `URLSearchParams.prototype.delete` method