fix: remove error message $ symbol (#19587)

Co-authored-by: 刘江波 <jiangbo721@163.com>
Co-authored-by: crazywoola <427733928@qq.com>

api/core/workflow/nodes/code/code_node.py

         depth: int = 1,
     ):
         if depth > dify_config.CODE_MAX_DEPTH:
-            raise DepthLimitError(f"Depth limit ${dify_config.CODE_MAX_DEPTH} reached, object too deep.")
+            raise DepthLimitError(f"Depth limit {dify_config.CODE_MAX_DEPTH} reached, object too deep.")
 
         transformed_result: dict[str, Any] = {}
         if output_schema is None: