bug: cannot apply without `--impure`

[nrdxp]

As of a recent update of nixos-unstable (maybe 2-3 weeks ago), I haven't been able to run colmena apply without adding the --impure argument due to colmena wanting to make some lockfile changes to it's "Internal Colmena Expressions" flake that get's placed in the /tmp directory.

I am a bit surprised nobody else reported this, so perhaps there is something about my particular flake (which is quite complex at this point) that could be causing this, but in any case, since it seems to be an internal colmena function to create this temporary flake, I figured it was worth reporting.

It may be as simply as running a nix flake lock on this temporary flake before doing anything else, but I don't understand enough what colmena is doing (yet) to say for sure.