You can actually keep the warning messages, saying “Your Password is Weak”, but still allow users to register with any password.
There are 5 different strength to return value indicates what strength you will allow a user to register with, if it is set to 0
a user can enter a single character as their password, so I would suggest setting to to _at least_ 1
.
add_filter('woocommerce_min_password_strength', function(){ return 1; }, 10);