Update Node.js version
Node.js v24 will become the active LTS release at the end of October. Once this happens we should update from our current version (v20).
See https://github.com/nodejs/release#release-schedule for updated schedule.
This involves updating the version specified in:
.nvmrc- E2E base image and test image
- release pipeline
- possibly some other references (we should try to minimise these)
See https://github.com/tektoncd/dashboard/pull/3719 for reference of a previous version bump.
This change would only affect developers working on the Dashboard project and should be transparent to users.
In the meantime, update to latest 20.x (20.19.3 as of today)
This is a prereq for https://github.com/tektoncd/dashboard/pull/4338 It requires npm v11.5.1 which is included from Node.js v24.5.0