Google AI's deprecation page [0] says that there is "No shutdown date announced" for gemini-2.5-flash-lite.

(Was your comment a joke? Or did google announce this through different channels?)

0: https://ai.google.dev/gemini-api/docs/deprecations

That’s the enterprise agent one, still available for API. Oh and I got it wrong… it’s actually 1500 searches per day free! Gemini Flash 2.5 also has this btw but I prefer Flash Lite to reduce costs. It’s nuts when you compare cost and features to any of the 3.x models. https://ai.google.dev/gemini-api/docs/pricing

Also if you use a newer API key (I think mine is from like Feb of this year) then you'll get a "this API key is too new to use 2.5" message.