BlenderBot2 search_queries not flushed.

[jxmsML]

Bug description
Whenever hasattr(self.model_api.retriever, 'search_queries') is True, the 'search_queries' field will be included in model act.
However, hasattr(self.model_api.retriever, 'search_queries') is always True once the model searched in previous turns in the same episode (even if in the current turn, the model chooses to retrieve from memory not search thus no search is performed)

Reproduction steps

parlai i -mf zoo:blenderbot2/blenderbot2_400M/model --search-server XXX  --knowledge-access-method classify --query-generator-model-file zoo:sea/bart_sq_gen/model --loglevel debug

Expected behavior
If no search is performed when generating the model response in some turn, no search_queries and top_docs fields should be set in the model act

Logs
Please paste the command line output:

Output goes here

Additional context
Add any other context about the problem here. (like proxy settings, network setup, overall goals, etc.)

[github-actions]

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[mojtaba-komeili]

Any update on this? I think this is what I noticed in the chatbot too.

[jxmsML]

I've merged the pr #4198