-Wstringop-truncation warning in socketmodule.c getsockaddrarg() for AF_ALG salg_name

Bug report

Bug description:

Building 3.14.5 with gcc 15.2 produces this warning:

    default: ./Modules/socketmodule.c: In function ‘getsockaddrarg’:
    default: ./Modules/socketmodule.c:2636:9: warning: ‘strncpy’ specified bound 64 equals destination size [-Wstringop-truncation]
    default:  2636 |         strncpy((char *)sa->salg_name, name, sizeof(sa->salg_name));
    default:       |         ^

Build environment: Ubuntu 26.04 LTS, gcc 15.2.0, configure with

./configure --enable-optimizations --with-lto --enable-bolt --enable-safety --enable-slower-safety --with-system-expat CXX=/usr/bin/g++ CFLAGS="-flto=auto" LDFLAGS="-flto=auto"

This looks like a false positive. I see this location reported in https://github.com/python/cpython/issues/94536 and there is a fix for a similar warning here:
https://github.com/matthiasgoergens/cpython/commit/c1fdddcf0f7b31a5954163bfd299115b1fa7799b

Would the following be a good fix that mirrors that older one?

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wstringop-truncation"
strncpy((char *)sa->salg_name, name, sizeof(sa->salg_name));
#pragma GCC diagnostic pop

CPython versions tested on:

3.14

Operating systems tested on:

Linux

Linked PRs

• gh-150022

从 Modules/socketmodule.c 中 getsockaddrarg() 对 AF_ALG 的处理开始，检查报告的 strncpy 警告。查看相关的 CPython issue 和链接的 PR gh-150022，然后使用报告中的 GCC 构建进行验证，确认警告已解决且未改变 socket 行为。