chore: use rimraf

Author: Eomm

package.json

@@ -9,7 +9,7 @@
     "lint:fix": "standard --fix",
     "unit": "tap test/**/*.test.js",
     "test": "npm run unit && npm run test:typescript",
-    "posttest": "rm test/fjs-generated*.js",
+    "posttest": "rimraf test/fjs-generated*.js",
     "test:typescript": "tsd"
   },
   "repository": {
@@ -25,6 +25,7 @@
   "homepage": "https://github.com/fastify/fast-json-stringify-compiler#readme",
   "devDependencies": {
     "fastify": "^4.0.0",
+    "rimraf": "^3.0.2",
     "sanitize-filename": "^1.6.3",
     "standard": "^17.0.0",
     "tap": "^16.0.0",