network: always check dynamic address assignments before entering configured state

Previously (v248 or earlier), even if no static address is configured,
the link did not enter configured state, as e.g. Link::static_addresses_configured
is false until the link gained its carrier.
But, after the commit 1187fc33, the
situation was changed. Static addresses, routes, and etc are requested even
if the link does not have its carrier, and thus the link enters configured
state when no static address and etc are specified.

This makes the link does not enter configured state before it gains its
carrier when at least one of dynamic address assignment protocols (e.g.
DHCP) except for NDISC is enabled.

Note that, unfortunately, netplan always enables ConfigureWithoutCarrier=
for all virtual devices, e.g. bridge. See,
https://github.com/canonical/netplan/commit/978e20f902f6b92a46dc6e0050e2172e834e4617
So, we need to support e.g. the following strange config:
```
[Netowkr]
ConfigureWithoutCarrier=yes
DHCP=yes
```

Fixes #19855.