Support --variants when using --output

[JeanChristopheMorinPerso]

Description

Add support for the --variants when also passing --output. This was technically already allowed, but the flag was never passed to the function being called.

Checklist - did you ...

• Add a file to the news directory (using the template) for the next release's release notes?
• Add / update necessary tests?
• Add / update outdated documentation?

[conda-bot]

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[codspeed-hq]

Merging this PR will not alter performance

✅ 5 untouched benchmarks

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_{Comparing JeanChristopheMorinPerso:support_variants_flag_for_output (337c927) with main (3d7576e)¹}

Footnotes

1. No successful run was found on main (1a557e9) during the generation of this report, so 3d7576e was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩