Fix ReFrame test step for RISC-V

[bedroge]

I ran into an issue with maturin not being available as a prebuilt wheel, and building from source requires rustc, so this PR adds it to the Debian Sid container.

Furthermore, the path to the CVMFS repo was hardcoded to /cvmfs/software.eessi.io, so I've also added some option to override that.

Finally, one step in the test task was missing the test tag, which means that the step was skipped if the playbook was run with -t test.

These changes allowed me to run the test suite:

Perform task: TASK: compatibility_layer : Run ReFrame tests (N)o/(y)es/(c)ontinue: *************************************************************************************************************************

TASK [compatibility_layer : Run ReFrame tests] *************************************************************************************************************************************************************
ok: [localhost]

[eessi-bot]

Instance eessi-bot-mc-aws is configured to build:

• arch x86_64/generic for repo eessi-hpc.org-2023.06-compat
• arch x86_64/generic for repo eessi-hpc.org-2023.06-software
• arch x86_64/generic for repo eessi.io-2023.06-compat
• arch x86_64/generic for repo eessi.io-2023.06-software
• arch x86_64/intel/haswell for repo eessi-hpc.org-2023.06-compat
• arch x86_64/intel/haswell for repo eessi-hpc.org-2023.06-software
• arch x86_64/intel/haswell for repo eessi.io-2023.06-compat
• arch x86_64/intel/haswell for repo eessi.io-2023.06-software
• arch x86_64/intel/skylake_avx512 for repo eessi-hpc.org-2023.06-compat
• arch x86_64/intel/skylake_avx512 for repo eessi-hpc.org-2023.06-software
• arch x86_64/intel/skylake_avx512 for repo eessi.io-2023.06-compat
• arch x86_64/intel/skylake_avx512 for repo eessi.io-2023.06-software
• arch x86_64/amd/zen2 for repo eessi-hpc.org-2023.06-compat
• arch x86_64/amd/zen2 for repo eessi-hpc.org-2023.06-software
• arch x86_64/amd/zen2 for repo eessi.io-2023.06-compat
• arch x86_64/amd/zen2 for repo eessi.io-2023.06-software
• arch x86_64/amd/zen3 for repo eessi-hpc.org-2023.06-compat
• arch x86_64/amd/zen3 for repo eessi-hpc.org-2023.06-software
• arch x86_64/amd/zen3 for repo eessi.io-2023.06-compat
• arch x86_64/amd/zen3 for repo eessi.io-2023.06-software
• arch aarch64/generic for repo eessi-hpc.org-2023.06-compat
• arch aarch64/generic for repo eessi-hpc.org-2023.06-software
• arch aarch64/generic for repo eessi.io-2023.06-compat
• arch aarch64/generic for repo eessi.io-2023.06-software
• arch aarch64/neoverse_n1 for repo eessi-hpc.org-2023.06-compat
• arch aarch64/neoverse_n1 for repo eessi-hpc.org-2023.06-software
• arch aarch64/neoverse_n1 for repo eessi.io-2023.06-compat
• arch aarch64/neoverse_n1 for repo eessi.io-2023.06-software
• arch aarch64/neoverse_v1 for repo eessi-hpc.org-2023.06-compat
• arch aarch64/neoverse_v1 for repo eessi-hpc.org-2023.06-software
• arch aarch64/neoverse_v1 for repo eessi.io-2023.06-compat
• arch aarch64/neoverse_v1 for repo eessi.io-2023.06-software

[boegel]

lgtm