CI: Broken `cachix`?

[HaoZeke]

Warning: The `save-state` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/
Cachix: installing
  /usr/bin/bash -c nix-env --quiet -j[8](https://github.com/d-SEAMS/seams-core/actions/runs/5308074653/jobs/9607199482?pr=27#step:6:9) -iA cachix -f https://cachix.org/api/v1/install
Cachix: using cache dseams
  Error: Action failed with error: Error: Unable to locate executable file: cachix. Please verify either the file path exists or the file can be found within a directory specified by the PATH environment variable. Also check the file mode to verify the file is executable.

Needs an update. Would be nice to perhaps step away from nix for now..