Deprecation warnings in the GitHub workflow `--update-input`

[ggreif]

I see warnings in the GitHub workflow log:

/nix/var/nix/profiles/default/bin/nix flake lock --update-input --commit-lock-file --option commit-lockfile-summary flake.lock: Update warning: '--update-input' is a deprecated alias for 'flake update' and will be removed in a future version.