Fix strict syntax in utils_* subworkflows

[itrujnara]

Removed names of single outputs in utils_* subworkflows to comply with Nextflow strict syntax. Edited metas to match. This should remove strict syntax warnings in pipelines.

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 subworkflows:
    • nf-core subworkflows test <SUBWORKFLOW> --profile docker
    • nf-core subworkflows test <SUBWORKFLOW> --profile singularity
    • nf-core subworkflows test <SUBWORKFLOW> --profile conda

[mashehu]

I thought we needed this for strict syntax a3fb735

[itrujnara]

I can't find the documentation for this, but nextflow lint shows a warning if a workflow has a single output and it is named. I have sent the warning message on Slack. I agree with Maxime that this rule should not be there, but that's the way Ben designed it.

[mashehu]

but in the current way i get the following with nextflow 26.04.4:

Warn  subworkflows/nf-core/utils_nfcore_pipeline/main.nf:16:5: Variable was declared but not used
│  16 |     valid_config = checkConfigProvided()
╰     |     ^^^^^^^^^^^^

Warn  subworkflows/nf-core/utils_nfcore_pipeline/main.nf:20:5: Emit name should be omitted when there is only one emit
│  20 |     valid_config
╰     |     ^^^^^^^^^^^^

that's why I had the previous version

[itrujnara]

I must have tested with a wrong version, with 26.04.4 it indeed returns these warnings. According to the docs the version without the extra name is correct. I am puzzled as to how I should write the emit section to avoid complaints from the language server.