fix: resolve mypy type errors in http_request and list_operator nodes

- Fix str | bytes union type handling in http_request executor
- Add type guard for boolean filter value in list_operator node

api/core/workflow/nodes/http_request/executor.py

             body_string += f"--{boundary}--\r\n"
         elif self.node_data.body:
             if self.content:
-                body_string = self.content.decode("utf-8", errors="replace")
+                if isinstance(self.content, bytes):
+                    body_string = self.content.decode("utf-8", errors="replace")
+                else:
+                    body_string = self.content
             elif self.data and self.node_data.body.type == "x-www-form-urlencoded":
                 body_string = urlencode(self.data)
             elif self.data and self.node_data.body.type == "form-data":

api/core/workflow/nodes/list_operator/node.py

                 result = list(filter(filter_func, variable.value))
                 variable = variable.model_copy(update={"value": result})
             else:
+                if not isinstance(condition.value, bool):
+                    raise ValueError(f"Boolean filter expects a boolean value, got {type(condition.value)}")
                 filter_func = _get_boolean_filter_func(condition=condition.comparison_operator, value=condition.value)
                 result = list(filter(filter_func, variable.value))
                 variable = variable.model_copy(update={"value": result})