Block the “Upgrade to Tahoe” alerts

I'm not ready to migrate (I refuse to call it an upgrade, so far) to Tahoe yet, and was very happy to see a path to silence/reduce the increasingly more insistent alerts.

Now I wish there was a way to do this on phones and tablets too.

Or you know, just upgrade. It barely changes anything.

I feel like the biggest idiot: I still haven't even noticed this "liquid glass" thing, and I am always on the bleeding edge betas for macOS etc. The last change I noticed to the way the OS looks was back in '07, I think. The big jump of course was from AppleDOS to the original Mac, and I did notice that one.