feat: Update minimum supported Node version to Node 20

PiperOrigin-RevId: 899095779

Author: sararob

.kokoro/test.sh

@@ -39,7 +39,7 @@ npm test
 
 # codecov combines coverage across integration and unit tests. Include
 # the logic below for any environment you wish to collect coverage for:
-COVERAGE_NODE=14
+COVERAGE_NODE=22
 if npx check-node-version@3.3.0 --silent --node $COVERAGE_NODE; then
   NYC_BIN=./node_modules/nyc/bin/nyc.js
   if [ -f "$NYC_BIN" ]; then

README.md

@@ -24,7 +24,7 @@ page in Vertex AI documentation.
 
 ## Before you begin
 
-1.  Make sure your node.js version is 18 or above.
+1.  Make sure your node.js version is 20 or above.
 1.  [Select](https://console.cloud.google.com/project) or [create](https://cloud.google.com/resource-manager/docs/creating-managing-projects#creating_a_project) a Google Cloud project.
 1.  [Enable billing for your project](https://cloud.google.com/billing/docs/how-to/modify-project).
 1.  [Enable the Vertex AI API](https://console.cloud.google.com/flows/enableapi?apiid=aiplatform.googleapis.com).

package.json

@@ -5,7 +5,7 @@
   "license": "Apache-2.0",
   "author": "Google LLC",
   "engines": {
-    "node": ">=18.0.0"
+    "node": ">=20.0.0"
   },
   "homepage": "https://github.com/googleapis/nodejs-vertexai",
   "repository": "googleapis/nodejs-vertexai",