build(docs-infra): replace concurrently with npm-run-all for preview server dev (#25671)

`npm-run-all` works just as well, but is better at handling termination on Windows.

PR Close #25671

aio/aio-builds-setup/dockerbuild/scripts-js/package.json

@@ -12,7 +12,7 @@
     "build-watch": "yarn ~~build-watch",
     "clean-dist": "node --eval \"require('shelljs').rm('-rf', 'dist')\"",
     "predev": "yarn build || true",
-    "dev": "concurrently --kill-others --raw --success first \"yarn ~~build-watch\" \"yarn ~~test-watch\"",
+    "dev": "run-p ~~build-watch ~~test-watch",
     "lint": "tslint --project tsconfig.json",
     "pretest": "yarn build",
     "test": "yarn ~~test-only",
@@ -44,8 +44,8 @@
     "@types/node-fetch": "^1.6.8",
     "@types/shelljs": "^0.8.0",
     "@types/supertest": "^2.0.3",
-    "concurrently": "^3.5.0",
     "nodemon": "^1.12.1",
+    "npm-run-all": "^4.1.3",
     "supertest": "^3.0.0",
     "tslint": "^5.7.0",
     "tslint-jasmine-noSkipOrFocus": "^1.0.8",