update waterdata test to skip on python 3.9 and older

Author: ehinman

tests/waterdata_test.py

@@ -1,8 +1,11 @@
 import datetime
-
+import sys
 import pytest
 from pandas import DataFrame
 
+if sys.version_info < (3, 10):
+    pytest.skip("Skip entire module on Python < 3.10", allow_module_level=True)
+
 from dataretrieval.waterdata import (
     _check_profiles,
     get_samples,