fix: dependencies package PEP508 markers selection

This bug was causing all cases to fall through to the default selection
by checkPythonVersions only.

With this commit the local .whl test succeeds because now poetry2nix can select
dependency markers for local .whl files.

Resolves #1174

Author: jamesdbrock

default.nix

@@ -180,10 +180,10 @@ lib.makeScope pkgs.newScope (self: {
       partitions =
         let
           supportsPythonVersion = pkgMeta:
-            if pkgMeta ? marker then
+            if pkgMeta ? markers then
               (
                 let
-                  marker = pyproject-nix.lib.pep508.parseMarkers pkgMeta.marker;
+                  marker = pyproject-nix.lib.pep508.parseMarkers pkgMeta.markers;
                 in
                 pyproject-nix.lib.pep508.evalMarkers pep508Env marker
               ) else true && poetryLib.checkPythonVersions pyVersion pkgMeta.python-versions;