[Cosmos] update changelog for cosmos release (#40301)

* update changelog for cosmos release

* Update test_backwards_compatibility_async.py

* Update test_backwards_compatibility_async.py

Author: simorenoh

sdk/cosmos/azure-cosmos/CHANGELOG.md

@@ -1,16 +1,10 @@
 ## Release History
 
-### 4.10.0b4 (Unreleased)
-
-#### Features Added
-
-#### Breaking Changes
+### 4.10.0b4 (2025-04-01)
 
 #### Bugs Fixed
 * Fixed bug introduced in 4.10.0b3 with explicitly setting `etag` keyword argument as `None` causing exceptions. See [PR 40282](https://github.com/Azure/azure-sdk-for-python/pull/40282).
 
-#### Other Changes
-
 ### 4.10.0b3 (2025-03-27)
 
 #### Bugs Fixed

sdk/cosmos/azure-cosmos/tests/test_backwards_compatibility_async.py

@@ -12,8 +12,8 @@
 from azure.cosmos.aio import CosmosClient, DatabaseProxy
 from azure.cosmos.exceptions import CosmosHttpResponseError
 
-@pytest.mark.cosmosLong
-class TestAutoScaleAsync(unittest.IsolatedAsyncioTestCase):
+@pytest.mark.cosmosEmulator
+class TestBackwardsCompatibilityAsync(unittest.IsolatedAsyncioTestCase):
     host = test_config.TestConfig.host
     masterKey = test_config.TestConfig.masterKey
     connectionPolicy = test_config.TestConfig.connectionPolicy
@@ -75,7 +75,7 @@ async def test_session_token_compatibility_async(self):
         assert replace_container is not None
         assert replace_container_read != container2_read
         assert 'defaultTtl' in replace_container_read # Check for default_ttl as a new additional property
-        assert replace_container_read['default_ttl'] == 30
+        assert replace_container_read['defaultTtl'] == 30
         await database.delete_container(replace_container.id, session_token=str(uuid.uuid4()))
         try:
             await container2.read()