[WarOnPrivacy]

This uBlock Origin custom filter suppresses the popup.

    ||accounts.google.com/gsi/*$xhr,script,3p

It's always the 1st one I install.

[pellucidar]

If you don't use uBlock Origin, you can also pihole or otherwise block the domain accounts.google.com. This is surprisingly non-destructive to active Google sessions, though you can't create new ones with it blocked.