sd-image: don't use installer.cloneConfig option that is not imported

This once again allows sd-image.nix to imported standalone to build SD images
of arbitrary NixOS systems.

nixos/doc/manual/configuration/profiles/clone-config.xml

@@ -16,6 +16,6 @@
   On images where the installation media also becomes an installation target,
   copying over <literal>configuration.nix</literal> should be disabled by
   setting <literal>installer.cloneConfig</literal> to <literal>false</literal>.
-  This is already done in <literal>sd-image.nix</literal>.
+  For example, this is done in <literal>sd-image-aarch64.nix</literal>.
  </para>
 </section>

nixos/modules/installer/cd-dvd/sd-image-aarch64.nix

@@ -59,4 +59,8 @@ in
       ${extlinux-conf-builder} -t 3 -c ${config.system.build.toplevel} -d ./files/boot
     '';
   };
+
+  # the installation media is also the installation target,
+  # so we don't want to provide the installation configuration.nix.
+  installer.cloneConfig = false;
 }

nixos/modules/installer/cd-dvd/sd-image-armv7l-multiplatform.nix

@@ -56,4 +56,8 @@ in
       ${extlinux-conf-builder} -t 3 -c ${config.system.build.toplevel} -d ./files/boot
     '';
   };
+
+  # the installation media is also the installation target,
+  # so we don't want to provide the installation configuration.nix.
+  installer.cloneConfig = false;
 }

nixos/modules/installer/cd-dvd/sd-image-raspberrypi.nix

@@ -45,4 +45,8 @@ in
       ${extlinux-conf-builder} -t 3 -c ${config.system.build.toplevel} -d ./files/boot
     '';
   };
+
+  # the installation media is also the installation target,
+  # so we don't want to provide the installation configuration.nix.
+  installer.cloneConfig = false;
 }

nixos/modules/installer/cd-dvd/sd-image.nix

@@ -194,9 +194,5 @@ in
         rm -f /nix-path-registration
       fi
     '';
-
-    # the installation media is also the installation target,
-    # so we don't want to provide the installation configuration.nix.
-    installer.cloneConfig = false;
   };
 }