circleci: Remove systemd from Fedora nsswitch configuration
circleci: Remove systemd from Fedora nsswitch configuration

Lest we end up with a non-functional user/group lookup, resulting in #15230.

sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc