[skip ci] Add comments for test case (#9026)

Signed-off-by: Binbin Lv <binbin.lv@zilliz.com>

tests/python_client/testcases/test_collection.py

@@ -2501,6 +2501,11 @@ class TestHasCollectionInvalid(object):
 
     @pytest.mark.tags(CaseLabel.L2)
     def test_has_collection_with_none_collection_name(self, connect):
+        """
+        target: test list collections with invalid scenario
+        method: show collection with no collection name
+        expected: raise exception
+        """
         collection_name = None
         with pytest.raises(Exception) as e:
             connect.has_collection(collection_name)