Add zstd to untar image

[JoseEspinosa]

Adding zstd to the untar image to enable to uncompress tar.zst files

PR checklist

• This comment contains a description of changes (with reason).
• Ensure that the test works with either Docker / Singularity. Conda CI tests can be quite flaky:
  • For modules:
    • nf-core modules test <MODULE> --profile docker
    • nf-core modules test <MODULE> --profile singularity
    • nf-core modules test <MODULE> --profile conda