chore: update node version in package.json

Author: angelcaamal

functions/v2/imagemagick/package.json

@@ -9,7 +9,7 @@
     "url": "https://github.com/GoogleCloudPlatform/nodejs-docs-samples.git"
   },
   "engines": {
-    "node": ">=16.0.0"
+    "node": ">=18.17.0"
   },
   "scripts": {
     "test": "c8 mocha -p -j 2 test/*.test.js --timeout=20000 --exit"