xarray: Add upstream patch to fix tests. (#28643)

pkgs/development/python-modules/xarray/default.nix

@@ -5,6 +5,7 @@
 , numpy
 , pandas
 , python
+, fetchurl
 }:
 
 buildPythonPackage rec {
@@ -17,6 +18,15 @@ buildPythonPackage rec {
     sha256 = "f649a41d43b5a6c64bdcbd57e994932656b689f9593a86dd0be95778a2b47494";
   };
 
+  # Temporary patch until next release (later than 0.9.6) to fix
+  # a broken test case.
+  patches = [
+    (fetchurl {
+      url = "https://github.com/pydata/xarray/commit/726c6a3638ecf95889c541d84e892a106c2f2f92.patch";
+      sha256 = "1i2hsj5v5qlvqfj48vyn9931yndsf4k4wrk3qpqpywh32s7r007b";
+    })
+  ];
+
   buildInputs = [ pytest ];
   propagatedBuildInputs = [numpy pandas];