core: simplify DnsNameResolver.resolveAddresses()

[panchenko]

resolveAddresses() is a private method, called only once. There is no need to handle exceptions in multiple places.

The reason for creating this PR:
I have noticed an exception like this in the logs

2025-10-16 13:09:33.141 WARN  [grpc-default-executor-222]    ManagedChannelImpl            [Channel<47>: (x.y.com:443)] Failed to resolve name. status=Status{code=UNAVAILABLE, 
description=Unable to resolve host x.y.com, 
cause=java.lang.RuntimeException: java.net.UnknownHostException: x.y.com: nodename nor servname provided, or not known
...
Caused by: java.net.UnknownHostException: x.y.com: nodename nor servname provided, or not known
...
}