HF RL Explorer

fix: apply SliceFlagSeparator to env var sources

fix: apply SliceFlagSeparator to env var sources: a task in repo2rlenv-pr-diff (Harbor dataset). Title: fix: apply SliceFlagSeparator to env var sources

The task

**Title:** fix: apply SliceFlagSeparator to env var sources

Part of FineEnvs/repo2rlenv-pr-diff.