Remove the second `if self.runtime is None:` check (#24171)

Co-authored-by: Yongtao Huang <99629139+hyongtao-db@users.noreply.github.com>

api/core/tools/custom_tool/tool.py

         return ToolProviderType.API
 
     def assembling_request(self, parameters: dict[str, Any]) -> dict[str, Any]:
+        headers = {}
         if self.runtime is None:
             raise ToolProviderCredentialValidationError("runtime not initialized")
 
-        headers = {}
-        if self.runtime is None:
-            raise ValueError("runtime is required")
         credentials = self.runtime.credentials or {}
-
         if "auth_type" not in credentials:
             raise ToolProviderCredentialValidationError("Missing auth_type")
 

api/core/tools/entities/api_entities.py

                         parameter.pop("input_schema", None)
         # -------------
         optional_fields = self.optional_field("server_url", self.server_url)
-        if self.type == ToolProviderType.MCP.value:
+        if self.type == ToolProviderType.MCP:
             optional_fields.update(self.optional_field("updated_at", self.updated_at))
             optional_fields.update(self.optional_field("server_identifier", self.server_identifier))
         return {