[RStudio] Update the version enums (remove 'ds-' + downgrade) (#37)

* Update enum version rstudio et rstudio-gpu

* Correction tags rstudio

(d'après https://hub.docker.com/r/inseefrlab/onyxia-rstudio/tags)

* children.yaml : update versions rstudio

* rstudio : update version (Chart.yaml)

* Update charts "enfants" de rstudio

(via generate-children-charts.py)