WP-NOW: Remove message about node v20 limitation for blueprints

[sejas]

What?

Remove message that asks for Node v20 when--blueprint param is present.

Why?

Since the polyfills were implemented on WordPress/wordpress-playground#882 , blueprints can be executed on Node v18

Testing Instructions

• Create a new blueprint file b.json with a valid blueprint like:

{
    "landingPage": "/wp-admin/",
    "features": {
        "networking": true
    },
    "steps": [
        {
            "step": "login",
            "username": "admin",
            "password": "password"
        }
    ]
}

• Run nvm use && npm install && npx nx run wp-now:build # nvm use will set the node version 18.18.2
• Run node dist/packages/wp-now/with-node-version.js start --blueprint=b.json
• Observe the blueprint runs as expected and there is no the following error This script is requires node version v20.0.0 or above when --blueprint=<file> is used; found v18.18.2

[adamziel]

Lovely!