[Cosmos] Fix signoff test command (Azure#13412)

Author: southpolesteve

sdk/cosmosdb/cosmos/package.json

@@ -72,7 +72,7 @@
     "test:node": "npm run build:test && npm run unit-test:node && npm run integration-test:node",
     "test-consumer": "rimraf consumer-test/node_modules consumer-test/package-lock.json && node consumer-test.js 2>&1",
     "test": "npm run unit-test && npm run integration-test",
-    "test:signoff": "mocha -r esm -r dotenv/config -r ./test/public/common/setup.js \"./test/internal/**/*.spec.ts\" \"./test/public/**/*.spec.ts\" --timeout 100000 --grep \"#nosignoff\" --invert",
+    "test:signoff": "npm run integration-test:node -- --fgrep \"nosignoff\" --invert",
     "unit-test:browser": "echo skipped",
     "unit-test:node": "echo skipped",
     "unit-test": "npm run unit-test:node && npm run unit-test:browser"