Replace dependency npm-run-all with npm-run-all2 ^5.0.0

Author: renovate[bot]

package.json

@@ -45,7 +45,7 @@
     "eslint-plugin-standard": "^4.0.0",
     "eslint-plugin-vue": "^9.0.0",
     "markdown-it-task-lists": "^2.1.1",
-    "npm-run-all": "^4.1.5",
+    "npm-run-all2": "^5.0.0",
     "prettier": "^2.4.0",
     "vue-github-button": "^1.0.7",
     "vuepress": "^1.2.0",