go to your LinkedIn account and select "Settings & Privacy," then "Data privacy"

then toggle off the "Data for generative AI improvement" option

it's very quick and easy but they did this all the way under the radar

(on the android app it's just called Settings, not Settings & Privacy, so ymmv)

I personally am more pro-genAI than a lot of folks i know -- my company has all but ordered us to use it, and I have to admit, it's insanely useful for certain applications. but there is so much fucked up, gross shit surrounding it, and so many unethical people and companies eagerly taking advantage, it makes my skin crawl.