nixos/make-options-doc: remove options postprocessing

with everything being rendered from markdown now we no longer need to
postprocess any options.xml that may be requested from elsewhere. we'll
don't need to keep the module path check either since that's done by
optionsJSON now.

nixos/lib/make-options-doc/default.nix

@@ -178,17 +178,6 @@ in rec {
       --varlist-id ${lib.escapeShellArg variablelistId} \
       --id-prefix ${lib.escapeShellArg optionIdPrefix} \
       ${optionsJSON}/share/doc/nixos/options.json \
-      options.xml
-
-    if grep /nixpkgs/nixos/modules options.xml; then
-      echo "The manual appears to depend on the location of Nixpkgs, which is bad"
-      echo "since this prevents sharing via the NixOS channel.  This is typically"
-      echo "caused by an option default that refers to a relative path (see above"
-      echo "for hints about the offending path)."
-      exit 1
-    fi
-
-    ${pkgs.libxslt.bin}/bin/xsltproc \
-      -o "$out" ${./postprocess-option-descriptions.xsl} options.xml
+      "$out"
   '';
 }