refactor: use script rather than command in daemon

modules/nix/linux-builder.nix

@@ -4,21 +4,6 @@ with lib;
 
 let
   cfg = config.nix.linux-builder;
-
-  # create-builder uses TMPDIR to share files with the builder, notably certs.
-  # macOS will clean up files in /tmp automatically that haven't been accessed in 3+ days.
-  # If we let it use /tmp, leaving the computer asleep for 3 days makes the certs vanish.
-  # So we'll use /run/org.nixos.linux-builder instead and clean it up ourselves.
-  script = pkgs.writeShellScript "linux-builder-start" ''
-    export TMPDIR=/run/org.nixos.linux-builder USE_TMPDIR=1
-    rm -rf $TMPDIR
-    mkdir -p $TMPDIR
-    trap "rm -rf $TMPDIR" EXIT
-    ${lib.optionalString cfg.ephemeral ''
-      rm -f ${cfg.workingDirectory}/${cfg.package.nixosConfig.networking.hostName}.qcow2
-    ''}
-    ${cfg.package}/bin/create-builder
-  '';
 in
 
 {
@@ -176,7 +161,22 @@ in
       environment = {
         inherit (config.environment.variables) NIX_SSL_CERT_FILE;
       };
-      command = "${script}";
+
+			# create-builder uses TMPDIR to share files with the builder, notably certs.
+			# macOS will clean up files in /tmp automatically that haven't been accessed in 3+ days.
+			# If we let it use /tmp, leaving the computer asleep for 3 days makes the certs vanish.
+			# So we'll use /run/org.nixos.linux-builder instead and clean it up ourselves.
+			script = ''
+				export TMPDIR=/run/org.nixos.linux-builder USE_TMPDIR=1
+				rm -rf $TMPDIR
+				mkdir -p $TMPDIR
+				trap "rm -rf $TMPDIR" EXIT
+				${lib.optionalString cfg.ephemeral ''
+					rm -f ${cfg.workingDirectory}/${cfg.package.nixosConfig.networking.hostName}.qcow2
+				''}
+				${cfg.package}/bin/create-builder
+			'';
+
       serviceConfig = {
         KeepAlive = true;
         RunAtLoad = true;