Discontinue support of Tsa, Daint, Dom in main

[dominichofer]

I propose to remove all mentioning and references of Tsa, Daint and Dom from spack-c2sm.
This would make spack-c2sm v0.21.1.1 the last working version on these machines and reduce the complexity of spack-c2sm significantly. Deployed instances or upstreams will remain on the machines until they're powered off.

I propose to do this now.

@jonasjucker @lxavier @mjaehn @samkellerhals @muellch @victoria-cherkas @cfkanesan @cosunae
Please add a 👍 if you agree or speak up if you don't. ty

[jonasjucker]

For Tsa and Dom 👍🏿

For Daint I would like to clarify/prepare some more things:

• COSMO is only built on Daint, but actually needed on Euler
• What about packages that are only built on Daint in general?

[dominichofer]

The natural consequences would be:

• COSMO would not be tested by CI. One could test it manually, for example before releasing a new version, or one could engineer an automated solution.
• Packages only built on Daint will need to be built with spack-c2sm v0.21.1.1 for the remaining lifetime of Daint.

[jonasjucker]

The following packages are only tested on Daint/Tsa but still needed on Euler after decomission of Daint:

• cosmo
• oasis
• int2lm
• libgrib1

[dominichofer]

cosmo-eccodes-definitions is tested on all machines: https://github.com/C2SM/spack-c2sm/blob/main/test/system_test.py#L80-L83

[jonasjucker]

#982 Should make the way free for the cleanup

[jonasjucker]

All done in #987