aiocoap.util.socknumbers module

This module contains numeric constants that would be expected in the socket module, but are not exposed there yet.

This module will be removed in favor of directly accessing socket constants once Python 3.13 support is dropped (see [issue 352](https://github.com/chrysn/aiocoap/issues/352)), with any remnants (decision on whether the RECVERR mechanism can be used) moved into the defaults module.

aiocoap.util.socknumbers.HAS_RECVERR = True

Indicates whether the discovered constants indicate that the Linux setsockopt(IPV6, RECVERR) / recvmsg(…, MSG_ERRQUEUE) mechanism is available