Remove unnecessary _retry_server_directed_only instance variables

Inline kwargs.get() at the single point of use in ThriftDatabricksClient
and SeaHttpClient instead of storing as dead instance state.

Signed-off-by: Shubham Dhal <shubham.dhal@databricks.com>

Author: sd-db

src/databricks/sql/backend/sea/utils/http_client.py

@@ -90,9 +90,6 @@ def __init__(
         )
         self._retry_delay_default = kwargs.get("_retry_delay_default", 5.0)
         self.force_dangerous_codes = kwargs.get("_retry_dangerous_codes", [])
-        self._retry_server_directed_only = kwargs.get(
-            "_retry_server_directed_only", False
-        )
 
         # Connection pooling settings
         self.max_connections = kwargs.get("max_connections", 10)
@@ -117,7 +114,7 @@ def __init__(
                 stop_after_attempts_duration=self._retry_stop_after_attempts_duration,
                 delay_default=self._retry_delay_default,
                 force_dangerous_codes=self.force_dangerous_codes,
-                server_directed_only=self._retry_server_directed_only,
+                server_directed_only=kwargs.get("_retry_server_directed_only", False),
                 urllib3_kwargs=urllib3_kwargs,
             )
         else:

src/databricks/sql/backend/thrift_backend.py

@@ -189,9 +189,6 @@ def __init__(
                 " This behaviour is deprecated and will be removed in a future release."
             )
         self.force_dangerous_codes = kwargs.get("_retry_dangerous_codes", [])
-        self._retry_server_directed_only = kwargs.get(
-            "_retry_server_directed_only", False
-        )
 
         additional_transport_args = {}
 
@@ -218,7 +215,7 @@ def __init__(
                 stop_after_attempts_duration=self._retry_stop_after_attempts_duration,
                 delay_default=self._retry_delay_default,
                 force_dangerous_codes=self.force_dangerous_codes,
-                server_directed_only=self._retry_server_directed_only,
+                server_directed_only=kwargs.get("_retry_server_directed_only", False),
                 urllib3_kwargs=urllib3_kwargs,
             )