ref(home-manager): don't use home-manager when building the host

When rebuilding the host (through `nixos-rebuild switch --flake`) I
don't want to rebuild also my home-manager configuration. I want these
to be two different steps.

I rebuild the home-manager configuration more frequently and it's a
waste of time and CPU to rebuild the world every time.

This is a pretty large refactoring:
- move checks back into the flake: if I modify a check, the
  configuration for `pre-commits` is not regenerated, as the file with the
  checks is not monitored with `direnv` (I could probably configure it for
  it, but not now)
- remove `home.nix` from the host level configuration
- introduce a `mkHomeManagerConfiguration` function to manage the
  different user@host
- fix a warning with the rust overlay

1 files changed, 2 insertions, 8 deletions

diff --git a/hosts/carmel/default.nix b/hosts/carmel/default.nix
index 00ae881..8971397 100644
--- a/hosts/carmel/default.nix
+++ b/hosts/carmel/default.nix
@@ -1,14 +1,8 @@
 { config, pkgs, hostname, ... }:
 
 {
-  imports = [
-    ./hardware.nix
-    ./boot.nix
-    ./sound.nix
-    ./networking.nix
-    ./home.nix
-    ./services.nix
-  ];
+  imports =
+    [ ./hardware.nix ./boot.nix ./sound.nix ./networking.nix ./services.nix ];
 
   # Allow setting GTK configuration using home-manager
   programs.dconf.enable = true;