Update package.json engines

Matching request at istanbuljs/istanbul-lib-processinfo#26 (comment)

Author: anomiex

package.json

@@ -4,7 +4,7 @@
   "description": "Wrap all spawned Node.js child processes by adding environs and arguments ahead of the main JavaScript file argument.",
   "main": "index.js",
   "engines": {
-    "node": ">=8"
+    "node": ">=14"
   },
   "dependencies": {
     "foreground-child": "^2.0.0",