DTLS Fixes

This release fixes the DTLS transport that was utterly broken in the initial delivery.

What's Changed

• Update msg.md by @ryosga in https://github.com/nanomsg/nng/pull/2142
• fixes #2146 need statistics for PUB protocol by @gdamore in https://github.com/nanomsg/nng/pull/2147
• Fix omnios clang-19 not found by @gdamore in https://github.com/nanomsg/nng/pull/2154
• fixes #2150 build error if HTTP support is disabled. by @gdamore in https://github.com/nanomsg/nng/pull/2153
• Gdamore/close notify by @gdamore in https://github.com/nanomsg/nng/pull/2152
• fixes #2148 Old id_reg_map seems not be freed by @gdamore in https://github.com/nanomsg/nng/pull/2155
• Bump socket common socket stats for PUB by @gdamore in https://github.com/nanomsg/nng/pull/2160
• minor improvements and a test case for DTLS by @gdamore in https://github.com/nanomsg/nng/pull/2161
• Gdamore/fix dtls by @gdamore in https://github.com/nanomsg/nng/pull/2166
• remaps EAI_AGAIN to NNG_EADDRINVAL by @jonhoo in https://github.com/nanomsg/nng/pull/2169
• fixes #2165 nng_http_handler_alloc_static crashes if content type is … by @gdamore in https://github.com/nanomsg/nng/pull/2170