Revert "network: configure DHCP clients after MAC address is assigned"
This reverts commit f42d41cc5f9cd8cac538a1c30fda04d346b5bae2.
DHCPv6 client does not require MAC address.
DHCPv4 client will be handled in a different way in a later commit.
Partially fixes #23546.
(cherry picked from commit 8f4f6307313ccad0b068697bb054a105e5a50e92)