feat(meta/*): support generalized deployments

Our colmena knows how to deal with families of system types, e.g. NixOS
systems or Liminix-based systems.

This is a step 1 towards supporting our APs in our infrastructure.

Signed-off-by: Ryan Lahfa <ryan@dgnum.eu>

lib/nix-lib/default.nix

@@ -42,6 +42,7 @@ rec {
     recursiveUpdate
     splitString
     unique
+    warn
     ;
 
   /*

lib/nix-lib/nixpkgs.nix

@@ -453,10 +453,10 @@ rec {
       # `builtins.warn` requires a string message, so we enforce that in our implementation, so that callers aren't accidentally incompatible with newer Nix versions.
       assert builtins.isString msg;
       if mustAbort then
-        builtins.trace "␛[1;31mevaluation warning:␛[0m ${msg}" (
+        builtins.trace "evaluation warning: ${msg}" (
           abort "NIX_ABORT_ON_WARN=true; warnings are treated as unrecoverable errors."
         )
       else
-        builtins.trace "␛[1;35mevaluation warning:␛[0m ${msg}" v
+        builtins.trace "evaluation warning: ${msg}" v
     );
 }