Remove template in unload to fix error on offline batch generation

src/distilabel/steps/tasks/text_generation.py

@@ -237,9 +237,12 @@ def check_column_in_template(column, template):
 
         for column in self.columns:
             check_column_in_template(column, self.template)
-        # NOTE: This should work, but when running on use_offline_batch_generation fails with a
-        # pickling error. This is a workaround to avoid the error.
-        # self._template = Template(self.template)
+
+        self._template = Template(self.template)
+
+    def unload(self) -> None:
+        super().unload()
+        self._template = None
 
     @property
     def inputs(self) -> "StepColumns":
@@ -251,8 +254,7 @@ def inputs(self) -> "StepColumns":
     def _prepare_message_content(self, input: Dict[str, Any]) -> "ChatType":
         """Prepares the content for the template and returns the formatted messages."""
         fields = {column: input[column] for column in self.columns}
-        # return [{"role": "user", "content": self._template.render(**fields)}]
-        return [{"role": "user", "content": Template(self.template).render(**fields)}]
+        return [{"role": "user", "content": self._template.render(**fields)}]
 
     def format_input(self, input: Dict[str, Any]) -> "ChatType":
         """The input is formatted as a `ChatType` assuming that the instruction