refactor(bazel): inline the primary user

configs/nixos/modules/shell/bazel.nix

@@ -5,14 +5,11 @@
   ...
 }:
 # Bazel for the primary user's shell environment.
-let
-  user = config.user.name;
-in
 {
   options.modules.shell.bazel.enable =
     lib.mkEnableOption "Bazel for the primary user's shell environment";
 
   config = lib.mkIf config.modules.shell.bazel.enable {
-    home-manager.users.${user}.home.packages = [ pkgs.bazel ];
+    home-manager.users.${config.user.name}.home.packages = [ pkgs.bazel ];
   };
 }