Ignore code coverage from fixtures

Author: Codex-

jest.config.ts

@@ -1,5 +1,6 @@
 import type { Config } from "@jest/types";
 const config: Config.InitialOptions = {
+  collectCoverageFrom: ["lib\\__fixtures__", "!lib\\__fixtures__"],
   globals: {
     "ts-jest": {
       tsconfig: "tsconfig.test.json",