Nightly tests and artefact uploading

[jl-wynen]

The nightly tests are still running in the old repos. And they are uploading reduced data files which are used by the DMSC nightly tests. We need to

• Disable nightlies in old repos
• Upload reduced files in ess nightlies (DREAM, ESTIA)
• Make sure those files are picked up by the DMSC nightly pipeline

[nvaytet]

We chatted about this today.
We would like to get around the uploading of artifact and then using another service to run a gh command to find the latest artifact and publish it on a stable url.

We will try to instead use a gh pre-release to publish the results (tried this today on the old essreflectometry repo.

[MridulS]

• [CI] Publish nightly reduced data files #596
• Update Analysis team and DMSC nightly pipeline with the new URLs
• Disable old repo nightlies
• Delete VM and Cloudflare R2 bucket