feat: Update the default NodeJS version in the examples (#437)

with a version that is available in the openshift/library.

Author: metlos

Diff for: .openshift/postgresql-template-persistent.json

@@ -442,8 +442,8 @@
     {
       "name": "NODEJS_VERSION",
       "displayName": "Version of NodeJS Image",
-      "description": "Version of NodeJS image to be used (14-ubi8, 16-ubi8, or latest).",
-      "value": "16-ubi8",
+      "description": "Version of NodeJS image to be used (18-ubi8, 20-ubi8, or latest).",
+      "value": "18-ubi8",
       "required": true
     },
     {

Diff for: .openshift/postgresql-template.json

@@ -425,8 +425,8 @@
     {
       "name": "NODEJS_VERSION",
       "displayName": "Version of NodeJS Image",
-      "description": "Version of NodeJS image to be used (14-ubi8, 16-ubi8, or latest).",
-      "value": "16-ubi8",
+      "description": "Version of NodeJS image to be used (18-ubi8, 20-ubi8, or latest).",
+      "value": "18-ubi8",
       "required": true
     },
     {