chore: cleanup unchanged overridden method in subclasses of BaseNode (#14281)

api/core/workflow/nodes/end/end_node.py

-from collections.abc import Mapping, Sequence
-from typing import Any
-
 from core.workflow.entities.node_entities import NodeRunResult
 from core.workflow.nodes.base import BaseNode
 from core.workflow.nodes.end.entities import EndNodeData
             inputs=outputs,
             outputs=outputs,
         )
-
-    @classmethod
-    def _extract_variable_selector_to_variable_mapping(
-        cls,
-        *,
-        graph_config: Mapping[str, Any],
-        node_id: str,
-        node_data: EndNodeData,
-    ) -> Mapping[str, Sequence[str]]:
-        """
-        Extract variable selector to variable mapping
-        :param graph_config: graph config
-        :param node_id: node id
-        :param node_data: node data
-        :return:
-        """
-        return {}

api/core/workflow/nodes/if_else/if_else_node.py

-from collections.abc import Mapping, Sequence
-from typing import Any, Literal
+from typing import Literal
 
 from typing_extensions import deprecated
 
 
         return data
 
-    @classmethod
-    def _extract_variable_selector_to_variable_mapping(
-        cls,
-        *,
-        graph_config: Mapping[str, Any],
-        node_id: str,
-        node_data: IfElseNodeData,
-    ) -> Mapping[str, Sequence[str]]:
-        """
-        Extract variable selector to variable mapping
-        :param graph_config: graph config
-        :param node_id: node id
-        :param node_data: node data
-        :return:
-        """
-        return {}
-
 
 @deprecated("This function is deprecated. You should use the new cases structure.")
 def _should_not_use_old_function(

api/core/workflow/nodes/iteration/iteration_start_node.py

-from collections.abc import Mapping, Sequence
-from typing import Any
-
 from core.workflow.entities.node_entities import NodeRunResult
 from core.workflow.nodes.base import BaseNode
 from core.workflow.nodes.enums import NodeType
-from core.workflow.nodes.iteration.entities import IterationNodeData, IterationStartNodeData
+from core.workflow.nodes.iteration.entities import IterationStartNodeData
 from models.workflow import WorkflowNodeExecutionStatus
 
 
         Run the node.
         """
         return NodeRunResult(status=WorkflowNodeExecutionStatus.SUCCEEDED)
-
-    @classmethod
-    def _extract_variable_selector_to_variable_mapping(
-        cls, graph_config: Mapping[str, Any], node_id: str, node_data: IterationNodeData
-    ) -> Mapping[str, Sequence[str]]:
-        """
-        Extract variable selector to variable mapping
-        :param graph_config: graph config
-        :param node_id: node id
-        :param node_data: node data
-        :return:
-        """
-        return {}

api/core/workflow/nodes/start/start_node.py

-from collections.abc import Mapping, Sequence
-from typing import Any
-
 from core.workflow.constants import SYSTEM_VARIABLE_NODE_ID
 from core.workflow.entities.node_entities import NodeRunResult
 from core.workflow.nodes.base import BaseNode
             node_inputs[SYSTEM_VARIABLE_NODE_ID + "." + var] = system_inputs[var]
 
         return NodeRunResult(status=WorkflowNodeExecutionStatus.SUCCEEDED, inputs=node_inputs, outputs=node_inputs)
-
-    @classmethod
-    def _extract_variable_selector_to_variable_mapping(
-        cls,
-        *,
-        graph_config: Mapping[str, Any],
-        node_id: str,
-        node_data: StartNodeData,
-    ) -> Mapping[str, Sequence[str]]:
-        return {}