nixos: Move uses of stdenv.shell to runtimeShell.

nixos/modules/system/activation/activation-script.nix

@@ -61,7 +61,7 @@ in
       apply = set: {
         script =
           ''
-            #! ${pkgs.stdenv.shell}
+            #! ${pkgs.runtimeShell}
 
             systemConfig=@out@
 

nixos/modules/system/boot/loader/grub/grub.nix

@@ -40,7 +40,7 @@ let
     { splashImage = f cfg.splashImage;
       grub = f grub;
       grubTarget = f (grub.grubTarget or "");
-      shell = "${pkgs.stdenv.shell}";
+      shell = "${pkgs.runtimeShell}";
       fullName = (builtins.parseDrvName realGrub.name).name;
       fullVersion = (builtins.parseDrvName realGrub.name).version;
       grubEfi = f grubEfi;
@@ -536,7 +536,7 @@ in
             btrfsprogs = pkgs.btrfs-progs;
           };
         in pkgs.writeScript "install-grub.sh" (''
-        #!${pkgs.stdenv.shell}
+        #!${pkgs.runtimeShell}
         set -e
         export PERL5LIB=${makePerlPath (with pkgs.perlPackages; [ FileSlurp XMLLibXML XMLSAX ListCompare ])}
         ${optionalString cfg.enableCryptodisk "export GRUB_ENABLE_CRYPTODISK=y"}

nixos/modules/system/boot/systemd.nix

@@ -241,37 +241,37 @@ let
         }
         (mkIf (config.preStart != "")
           { serviceConfig.ExecStartPre = makeJobScript "${name}-pre-start" ''
-              #! ${pkgs.stdenv.shell} -e
+              #! ${pkgs.runtimeShell} -e
               ${config.preStart}
             '';
           })
         (mkIf (config.script != "")
           { serviceConfig.ExecStart = makeJobScript "${name}-start" ''
-              #! ${pkgs.stdenv.shell} -e
+              #! ${pkgs.runtimeShell} -e
               ${config.script}
             '' + " " + config.scriptArgs;
           })
         (mkIf (config.postStart != "")
           { serviceConfig.ExecStartPost = makeJobScript "${name}-post-start" ''
-              #! ${pkgs.stdenv.shell} -e
+              #! ${pkgs.runtimeShell} -e
               ${config.postStart}
             '';
           })
         (mkIf (config.reload != "")
           { serviceConfig.ExecReload = makeJobScript "${name}-reload" ''
-              #! ${pkgs.stdenv.shell} -e
+              #! ${pkgs.runtimeShell} -e
               ${config.reload}
             '';
           })
         (mkIf (config.preStop != "")
           { serviceConfig.ExecStop = makeJobScript "${name}-pre-stop" ''
-              #! ${pkgs.stdenv.shell} -e
+              #! ${pkgs.runtimeShell} -e
               ${config.preStop}
             '';
           })
         (mkIf (config.postStop != "")
           { serviceConfig.ExecStopPost = makeJobScript "${name}-post-stop" ''
-              #! ${pkgs.stdenv.shell} -e
+              #! ${pkgs.runtimeShell} -e
               ${config.postStop}
             '';
           })