refactor(rubygems): Decouple metadata fetching from versions fetching (#22808)

Co-authored-by: lluiscab <lluiscab@gmail.com>
Co-authored-by: HonkingGoose <34918129+HonkingGoose@users.noreply.github.com>
Co-authored-by: Michael Kriese <michael.kriese@visualon.de>
Co-authored-by: Rhys Arkins <rhys@arkins.net>
Co-authored-by: t-kulmburg <89128736+t-kulmburg@users.noreply.github.com>
Co-authored-by: Victor Engmark <victor@engmark.name>