What I'd suggest is adapt to it, find ways to push back. Obviously things like "delete entire unit test file & have claude generate a new one" is a bad idea. I've seen claude "monkey patching" a system so that it returns true to the tests.
This issue is going to pop up in the future. Experiment with it on the company's dime even if you've checked out emotionally. You are still doing your job - improving code quality and making sure things run.
The new approach seems to be doing TDD. One, as an engineer, you'll know when AI is bullshitting you with mocks. Even when mocks are BS, you can still test the thing they're meant to represent. 2) AI spits more code than anyone can review. The red, green, refactor approach is one way to keep them on the rails.