[Fixes #52118273] Apply no-hosts option to clients as well

Move the `no-hosts` option from the server config to the default (used by
both server and client).

nsswitch/glibc/whatever should always check `hosts(5)` first, anyway.
There's no need for dnsmasq to ever serve these entries up. It will only
lead to confusion.

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Tested with https://github.com/alphagov/puppet-inabox/tree/dns