Temporary disable AES256ColumnEncryptionPolicy

There was some seriouse issues in policy implementation in `3.27.0`.
We want to inspect the feature before making it available.

cassandra/column_encryption/_policies.py

@@ -45,6 +45,7 @@ class AES256ColumnEncryptionPolicy(ColumnEncryptionPolicy):
     # preserved or else you will not be able to decrypt any data encrypted by this
     # policy.
     def __init__(self, iv=None):
+        raise Exception("AES256ColumnEncryptionPolicy is temporary disabled, until https://github.com/scylladb/python-driver/issues/365 is sorted out")
 
         # CBC uses an IV that's the same size as the block size
         #

tests/integration/standard/column_encryption/test_policies.py

@@ -25,6 +25,7 @@
 def setup_module():
     use_singledc()
 
+@unittest.skip("Skip until https://github.com/scylladb/python-driver/issues/365 is sorted out")
 class ColumnEncryptionPolicyTest(unittest.TestCase):
 
     def _recreate_keyspace(self, session):