Pools in example configurations conflict

I know pools are the first thing an administrator changes in a real environment, but then there are developers who try to come up with a fast local setup and take inspiration from example configurations. And then they stumble upon

DHCP6_INIT_FAIL [..] subnet configuration failed: a pool of type IA_PD, with the following address range: 2001:db8::-2001:db8:ff:ffff:ffff:ffff:ffff:ffff overlaps with an existing pool in the subnet: 2001:db8::/32 to which it is being added

This is the case for kea6/all-keys.json, but there might be others. Pools can be easily changed to not come into conflict, so let's do that.