black-macchiato: Fix failing tests

pkgs/development/python-modules/black-macchiato/default.nix

···
   pythonOlder,
   pytestCheckHook,
   black,
+  fetchpatch,
 }:
 
 buildPythonPackage rec {
···
     rev = version;
     sha256 = "0lc9w50nlbmlzj44krk7kxcia202fhybbnwfh77xixlc7vb4rayl";
   };
+
+  patches = [
+    # fix empty multi-line string test
+    (fetchpatch {
+      url = "https://github.com/wbolster/black-macchiato/commit/d3243a1c95b5029b3ffa12417f0c587a2ba79bcd.patch";
+      hash = "sha256-3m8U6c+1UCRy/Fkq6lk9LhwrFyE+q3GD2jnMA7N4ZJs=";
+    })
+  ];
 
   propagatedBuildInputs = [ black ];