Grant read-only rights to backup user for PostgreSQL

This one comes up quite regularly, so worthy of note:

postgres=# drop database family;
DROP DATABASE
postgres=# create database family owner family;
CREATE DATABASE
postgres=# \c family
You are now connected to database "family" as user "postgres".
family=# GRANT SELECT ON ALL TABLES IN SCHEMA public to backups;
GRANT
family=# GRANT SELECT ON ALL SEQUENCES IN SCHEMA public to backups;
GRANT
family=# ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO backups;
ALTER DEFAULT PRIVILEGES
family=# ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON SEQUENCES TO backups;
ALTER DEFAULT PRIVILEGES