Reactivate env -i for CI #1049
Description
In order to clone private repos we need to have some git-config env variables with cscs-ci.
So far we started any. spack command prefixed by env -i, to reduce side-effects.
Unfortunately this also removes the required git-config vars.
Explicitly setting them
env --ignore-environment GIT_CONFIG_COUNT=1 GIT_CONFIG_KEY_0=url.https://oauth2:MyActualToken@gitlab.dkrz.de/.insteadOf GIT_CONFIG_VALUE_0="git@gitlab.dkrz.de:" my_command
will expose the keys in case the subprocess fails.
We do not want that.