Fix incorrect references to packagecloud.io

Axel von Bertoldirequested to merge
avonbertoldi/38031/pkgclould-urls into main

Replace all references to packagecloud.io with our own packageckoud instance at packages.gitlab.com to avoid confusion.

Note that there are still a couple of references to packagecloud.io in the docs, but they are correct as they are instructions on how to install git-lfs, whose packages ARE hosted on packagecloud.com

Closes #38031+

Edited by Axel von Bertoldi

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