Fix orekit data repo URL

• Only after merge of orekit/orekit-data!4 (merged) : this merge request replaces the URL https://gitlab.orekit.org/yzokras/orekit-data.git in the conda environments by https://gitlab.orekit.org/orekit/orekit-data.git

• Once !5 (merged) is merged, rebase this branch onto the master