ci: remove artifact branches.list

This patch reverts partially !344 (merged) and removes branches.list artifact. We've decided to fetch it on side of infra ci.

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• Follow-up for !344 (merged)
• See also https://git.picodata.io/picodata/web-site/infra/-/issues/2#note_65545
• Target branch: main
• Changes should be cherry-picked to 24.1: no