unbreak ::text for json in pg (#4722)

* unbreak ::text for json in pg

* better error handling

backend/windmill-worker/src/pg_executor.rs

@@ -583,6 +583,11 @@ fn convert_val(
                 .unwrap_or(vec![]);
             Ok(Box::new(bytes))
         }
+        Value::Object(_) if arg_t == "text" || arg_t == "varchar" => {
+            Ok(Box::new(serde_json::to_string(value).map_err(|err| {
+                Error::ExecutionErr(format!("Failed to convert JSON to text: {}", err))
+            })?))
+        }
         Value::Object(_) => Ok(Box::new(value.clone())),
         Value::String(s) => Ok(Box::new(s.clone())),
         _ => Err(Error::ExecutionErr(format!(