refactor(hosts): remove redundant host and system arguments

Remove explicit `host` and `system` definitions from `specialArgs` in
various host `default.nix` files. These values are redundant as they
can be derived from the flake context or are already provided by the
calling environment.

modules/hosts/14900k/default.nix

@@ -4,8 +4,6 @@
     system = "x86_64-linux";
     specialArgs = {
       inherit self inputs;
-      host = "14900k";
-      system = "x86_64-linux";
     };
     modules = [
       self.nixosModules."14900kConfiguration"

modules/hosts/ideapad/default.nix

@@ -4,8 +4,6 @@
     system = "aarch64-linux";
     specialArgs = {
       inherit self inputs;
-      host = "ideapad";
-      system = "aarch64-linux";
     };
     modules = [
       self.nixosModules.ideapadConfiguration

modules/hosts/nix-server/default.nix

@@ -3,8 +3,6 @@
     system = "x86_64-linux";
     specialArgs = {
       inherit self inputs;
-      host = "nix-server";
-      system = "x86_64-linux";
     };
     modules = [
       self.nixosModules.nix-serverConfiguration

modules/hosts/r5500/default.nix

@@ -3,8 +3,6 @@
     system = "x86_64-linux";
     specialArgs = {
       inherit self inputs;
-      host = "r5500";
-      system = "x86_64-linux";
     };
     modules = [
       self.nixosModules.r5500Configuration

modules/hosts/t2mbp/default.nix

@@ -4,8 +4,6 @@
     system = "x86_64-linux";
     specialArgs = {
       inherit self inputs;
-      host = "t2mbp";
-      system = "x86_64-linux";
     };
     modules = [
       self.nixosModules.t2mbpConfiguration

modules/hosts/uConsole/default.nix

@@ -4,8 +4,6 @@
     specialArgs = inputs // {
       inherit self;
       inputs = inputs;
-      host = "uConsole";
-      system = "aarch64-linux";
     };
     trustCaches = false;
     modules = [