nixos: Move uses of stdenv.shell to runtimeShell.

nixos/modules/programs/rootston.nix

@@ -6,7 +6,7 @@ let
   cfg = config.programs.rootston;
 
   rootstonWrapped = pkgs.writeScriptBin "rootston" ''
-    #! ${pkgs.stdenv.shell}
+    #! ${pkgs.runtimeShell}
     if [[ "$#" -ge 1 ]]; then
       exec ${pkgs.rootston}/bin/rootston "$@"
     else

nixos/modules/programs/ssh.nix

@@ -13,7 +13,7 @@ let
 
   askPasswordWrapper = pkgs.writeScript "ssh-askpass-wrapper"
     ''
-      #! ${pkgs.stdenv.shell} -e
+      #! ${pkgs.runtimeShell} -e
       export DISPLAY="$(systemctl --user show-environment | ${pkgs.gnused}/bin/sed 's/^DISPLAY=\(.*\)/\1/; t; d')"
       exec ${askPassword}
     '';