remove redundant setting of ARCHIVE_UNIQUE_ID in win artefact script

[h-vetinari]

Noticed that the following is fully redundant, and actually undoes the %SHORT_CONFIG% logic, see

conda-smithy/conda_smithy/templates/create_conda_build_artifacts.bat.tmpl

Lines 33 to 40 in c9a3fbb

	rem Set a unique ID for the artifact(s), specialized for this particular job run
	set ARTIFACT_UNIQUE_ID=%CI_RUN_ID%_%CONFIG%
	if not "%ARTIFACT_UNIQUE_ID%" == "%ARTIFACT_UNIQUE_ID:~0,80%" (
	set ARTIFACT_UNIQUE_ID=%CI_RUN_ID%_%SHORT_CONFIG%
	)
	rem Set a descriptive ID for the archive(s), specialized for this particular job run
	set ARCHIVE_UNIQUE_ID=%CI_RUN_ID%_%CONFIG%

[beckermr]

could use a news item?

[h-vetinari]

could use a news item?

It's ultra-niche, so I think it'd be fine even without. I also haven't added a news-item yet, because I'm expecting several changes related to artefact persistence (on GHA) coming from conda-forge/pytorch-cpu-feedstock#395. I'm chasing down one last bug currently.

Fine by me to wait here or merge this newslessly. I just opened a PR right away to not forget about this redundancy once I stumbled over it.

[h-vetinari]

There's now a news file in #2347 :)