Fix memory leak when printing any error's source code. (#12831)

Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>

test/js/bun/util/inspect-error-leak.test.js

@@ -0,0 +1,23 @@
+import { test, expect } from "bun:test";
+
+const perBatch = 2000;
+const repeat = 50;
+test("Printing errors does not leak", () => {
+  function batch() {
+    for (let i = 0; i < perBatch; i++) {
+      Bun.inspect(new Error("leak"));
+    }
+    Bun.gc(true);
+  }
+
+  batch();
+  const baseline = Math.floor(process.memoryUsage.rss() / 1024);
+  for (let i = 0; i < repeat; i++) {
+    batch();
+  }
+
+  const after = Math.floor(process.memoryUsage.rss() / 1024);
+  const diff = ((after - baseline) / 1024) | 0;
+  console.log(`RSS increased by ${diff} MB`);
+  expect(diff, `RSS grew by ${diff} MB after ${perBatch * repeat} iterations`).toBeLessThan(10);
+}, 10_000);