Include current or compatible node versions in the upgrade guides

[AlexanderFalkenberg]

While updating to a later 5.x version, we had a problem with the control panel

ReferenceError: copyToClipboardModalUrl is not defined at Vue$3.eval (eval at createFunction (app-cd5758db.js:7:25332), <anonymous>:7:113938) at M._render (app-cd5758db.js:5:24987) at Vue$3.N (app-cd5758db.js:5:29723) at M.get (app-cd5758db.js:5:42279) at new M (app-cd5758db.js:5:42188) at mountComponent (app-cd5758db.js:5:29824) at Vue$3.$mount (app-cd5758db.js:5:102964) at Vue$3.$mount (app-cd5758db.js:9:800) at M._init (app-cd5758db.js:5:48077) at new Vue$3 (app-cd5758db.js:5:57073)

We resolved it by upgrading to a later node version from 18 to 22. A hint which node version is currently used in the statamic/core and cp would be helpful in future upgrade guides. I only noticed since it worked on a more up-to-date local and staging environment, but not on prod.