chore(nix): use mkShellNoCC for lighter dev shell (#286)

Switch from mkShell to mkShellNoCC since this project doesn't require
a C compiler toolchain. This reduces unnecessary dependencies and
speeds up shell initialisation for Node.js/pnpm development.

Author: ryoppippi

flake.nix

@@ -22,7 +22,7 @@
           pkgs = nixpkgs.legacyPackages.${system};
         in
         {
-          default = pkgs.mkShell {
+          default = pkgs.mkShellNoCC {
             buildInputs = with pkgs; [
               # runtime
               nodejs_24