feat: Update package.json to require node >= 20 (#346)

Author: jirispilka

package-lock.json

@@ -5,7 +5,7 @@
   "description": "Apify MCP Server",
   "mcpName": "com.apify/apify-mcp-server",
   "engines": {
-    "node": ">=18.0.0"
+    "node": ">=20.0.0"
   },
   "main": "dist/index.js",
   "exports": {
@@ -82,7 +82,6 @@
     "start": "npm run start:dev",
     "start:prod": "node dist/main.js",
     "start:dev": "tsx src/main.ts",
-    "start:standby": "APIFY_META_ORIGIN=STANDBY npm run start",
     "lint": "eslint .",
     "lint:fix": "eslint . --fix",
     "build": "tsc -b src",