nixos/prometheus: fix cross-compilation

nixos/modules/services/monitoring/prometheus/alertmanager.nix

···
 
   checkedConfig = file:
     if cfg.checkConfig then
-      pkgs.runCommand "checked-config" { buildInputs = [ cfg.package ]; } ''
+      pkgs.runCommand "checked-config" { nativeBuildInputs = [ cfg.package ]; } ''
         ln -s ${file} $out
         amtool check-config $out
       '' else file;

nixos/modules/services/monitoring/prometheus/default.nix

···
     if checkConfigEnabled then
       pkgs.runCommandLocal
         "${name}-${replaceStrings [" "] [""] what}-checked"
-        { buildInputs = [ cfg.package.cli ]; } ''
+        { nativeBuildInputs = [ cfg.package.cli ]; } ''
         ln -s ${file} $out
         promtool ${what} $out
       '' else file;

nixos/modules/services/monitoring/prometheus/exporters/blackbox.nix

···
   checkConfig = file:
     pkgs.runCommand "checked-blackbox-exporter.conf" {
       preferLocalBuild = true;
-      buildInputs = [ pkgs.buildPackages.prometheus-blackbox-exporter ];
+      nativeBuildInputs = [ pkgs.buildPackages.prometheus-blackbox-exporter ];
     } ''
       ln -s ${coerceConfigFile file} $out
       blackbox_exporter --config.check --config.file $out