Update spack recipe and RELEASE docs

[ClaudiaComito]

Feature functionality
I'm not 100% sure but I think we need to create a new spack recipe for every release.

Also, RELEASE.md needs to be updated with relevant instructions.

[mrfh92]

I have contacted Sven (who was originally working on this) on this issue... may he knows more on how to keep versions up to date in spack

[ClaudiaComito]

Let's get a couple lines of instructions from Sven, so next time we can update the recipe ourselves right after a release, what do you think @mrfh92 ?

[mrfh92]

As far as I understand, one has to create a new PR in the spack repo and to manually add the new version and its dependencies: spack/spack#44835

[github-actions]

This issue is stale because it has been open for 60 days with no activity.