ref(utils): Remove Object.setPrototypeOf polyfill (#5087)

Now that we're ES6-only, we no longer need to polyfill `Object.setPrototypeOf`. (The last browser to gain support for it did so in September of 2015[1].)

[1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/setPrototypeOf#browser_compatibility

Author: lobsterkatie

packages/utils/src/error.ts

@@ -1,5 +1,3 @@
-import { setPrototypeOf } from './polyfill';
-
 /** An error emitted by Sentry SDKs and related utilities. */
 export class SentryError extends Error {
   /** Display name of this error instance. */
@@ -9,6 +7,6 @@ export class SentryError extends Error {
     super(message);
 
     this.name = new.target.prototype.constructor.name;
-    setPrototypeOf(this, new.target.prototype);
+    Object.setPrototypeOf(this, new.target.prototype);
   }
 }