TEST: Mark file:/// URL test as xfail

Author: effigies

nibabel/tests/test_image_api.py

@@ -579,6 +579,10 @@ def validate_from_url(self, imaker, params):
         del img
         del rt_img
 
+    @pytest.mark.xfail(
+        sys.version_info >= (3, 12),
+        reason='Response type for file: urls is not a stream in Python 3.12',
+    )
     def validate_from_file_url(self, imaker, params):
         tmp_path = self.tmp_path