socket.gethostbyaddr does not work with IPv6 on Solaris

Bug report

Bug description:

The documentation suggests that socket.gethostbyaddr supports both IPv4 and IPv6:
https://docs.python.org/3/library/socket.html#socket.gethostbyaddr
however, gethostbyaddr_r on Solaris does not support IPv6.

Solaris/Illumos provide platform-specific getipnodebyaddr function which can be used to lookup IPv6 addresses.

I did not test this with Illumos, but the man page suggest the same behavior as with Oracle Solaris:
https://www.smartos.org/man/3nsl/gethostbyaddr_r

"the functions described in the following cannot be used with applications targeted to work with IPv6."

CPython versions tested on:

CPython main branch, 3.13, 3.11

Operating systems tested on:

Other

Linked PRs

• gh-157498

从 socket.gethostbyaddr 入口点开始，检查 CPython 在 Solaris 上如何调用 gethostbyaddr_r。将该路径与 issue 中描述的特定于平台的 getipnodebyaddr 行为进行比较，并查看关联的 PR gh-157498。当 IPv6 反向查找能够在 Solaris 上正常工作且不破坏现有 IPv4 行为时，即视为完成。