chore(package): remove duplicate script (#549)

Both `lint` and `test:lint` do the same thing. Just use `lint` to keep inline with other Fastify repos.

Author: Fdawgs

package.json

@@ -11,12 +11,11 @@
     "benchmark": "node ./benchmark/bench-cmp-lib.js",
     "lint": "standard",
     "lint:fix": "standard --fix",
-    "test:lint": "standard",
     "test:typescript": "tsc --project ./test/types/tsconfig.json && tsd",
     "test:unit": "tap -J test/*.test.js test/**/*.test.js",
     "test": "npm run test:unit && npm run test:typescript"
   },
-  "precommit": ["test:lint", "test"],
+  "precommit": ["lint", "test"],
   "repository": {
     "type": "git",
     "url": "git+https://github.com/fastify/fast-json-stringify.git"