Revisit support for Spack target architectures, to match Nextflow inputs

[marcodelapierre]

We want to make sure we are able to build Wave Containers with target micro-architectures that are relevant/useful to the service.

Current status:

• Nextflow: see Revisit support for Spack target architectures, for best fit with Wave requirements nextflow-io/nextflow#4523
• Wave backend currently restricts legal Spack platform values to either x86_64 or aarch64 (or equivalent), see https://github.com/seqeralabs/wave/blob/master/src/main/groovy/io/seqera/wave/util/SpackHelper.groovy#L54-L63

TO-DO:

• Nextflow side: see Revisit support for Spack target architectures, for best fit with Wave requirements nextflow-io/nextflow#4523
• Wave backend side: wider list of targets to be accepted (at minimum, add x86_64_v3)
• Wave backend side: diversify between container platform required for container builder and target for Spack commands in containerfile
  • eg see https://github.com/seqeralabs/wave/blob/master/src/main/groovy/io/seqera/wave/core/ContainerPlatform.groovy#L103-L114
  • likely need to have distinct attributes for container platform vs spack target

For reference, list of Spack supported targets as of today: https://spack.readthedocs.io/en/latest/basic_usage.html#support-for-specific-microarchitectures

[pditommaso]

Spack support is Sunsetting #531