issue warning about state of open data stores and xfail tests that do…

… not work with numpy 2.x

src/maggma/stores/open_data.py

@@ -1,4 +1,5 @@
 import gzip
+import logging
 import re
 from collections.abc import Generator
 from datetime import datetime
@@ -53,6 +54,11 @@ def __init__(
         self._data = None
         self.key = key
         self.last_updated_field = last_updated_field
+        self.logger = logging.getLogger(type(self).__name__)
+        self.logger.addHandler(logging.NullHandler())
+        self.logger.warning(
+            "Use all open data stores with caution. The stores are in a a deprecated, and in particular may be incompatible with numpy 2.0+."
+        )
 
     @property
     def index_data(self):

tests/stores/test_open_data.py

@@ -390,6 +390,9 @@ def test_read_doc_from_s3():
         assert (df["task_id"] == "mp-2").any()
 
 
+@pytest.mark.xfail(
+    reason="Known issue, the store is in a deprecated state, and in particular may be incompatible with numpy 2.0+"
+)
 def test_update(s3store):
     assert len(s3store.index_data) == 2
     s3store.update(