Nextflow lint results

⚠️ Warnings

Warning: subworkflows/nf-core/utils_nextflow_pipeline/main.nf:43:5: Emit name should be omitted when there is only one emit
```
    dummy_emit = true
    ^^^^^^^^^^^^^^^
```
Warning: subworkflows/nf-core/utils_nfcore_pipeline/main.nf:20:5: Emit name should be omitted when there is only one emit
```
    valid_config = valid_config
    ^^^^^^^^^^^^^^^^^^^^^^^^^
```
Warning: subworkflows/nf-core/utils_nfschema_plugin/main.nf:72:5: Emit name should be omitted when there is only one emit
```
    dummy_emit = true
    ^^^^^^^^^^^^^^^
```
Warning: workflows/provenancereport.nf:19:5: Parameter was not used -- prefix with _ to suppress warning
```
    ch_samplesheet // channel: samplesheet read in from --input
    ^^^^^^^^^^^^^^
```

Warning: workflows/provenancereport.nf:46:9: Variable was declared but not used

    def ch_collated_versions = softwareVersionsToYAML(ch_versions.mix(topic_versions.versions_file))
        ^^^^^^^^^^^^^^^^^^^^

Warning: workflows/provenancereport.nf:55:5: Emit name should be omitted when there is only one emit

    versions       = ch_versions                 // channel: [ path(versions.yml) ]
    ^^^^^^^^^^^^^^^^^^^^