Twenty Nineteen: Update package.json with the latest package versions to pass npm audit.

Props netweb.
Fixes #47631.

git-svn-id: https://develop.svn.wordpress.org/trunk@45594 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-content/themes/twentynineteen/package.json

@@ -7,12 +7,12 @@
   },
   "homepage": "https://github.com/WordPress/twentynineteen#readme",
   "devDependencies": {
-    "@wordpress/browserslist-config": "^2.2.2",
-    "autoprefixer": "^9.1.5",
-    "chokidar-cli": "^1.2.1",
-    "node-sass": "^4.9.3",
+    "@wordpress/browserslist-config": "^2.5.0",
+    "autoprefixer": "^9.6.0",
+    "chokidar-cli": "^1.2.2",
+    "node-sass": "^4.12.0",
     "npm-run-all": "^4.1.5",
-    "postcss-cli": "^6.0.1",
+    "postcss-cli": "^6.1.2",
     "postcss-focus-within": "^3.0.0",
     "rtlcss": "^2.4.0"
   },