New release for msgpack-c?

[theoparis]

CMake 4.0 is out now and msgpack-c cannot be compiled with it on Gentoo due to cmake <3.5 support being dropped.

[redboltz]

It seems that there is no practical way to support both cmake < 3.5 and 4.0
It is a time to drop cmake < 3.5 support. Most of platform has cmake >= 3.5.

Distro	Support Status (as of 2025)	Default CMake Version (example)
Ubuntu 16.04	ESM only (regular support ended)	3.5.1
Ubuntu 18.04	ESM (Extended Security Maintenance)	3.10.2
Ubuntu 20.04	LTS (Long Term Support)	3.16.3
Debian 9 (Stretch)	EOL (End of Life)	3.7.2
Debian 10 (Buster)	LTS	3.13.4
CentOS 7	Near EOL (June 2024)	2.8.12 (*3.x available via SCL)
RHEL 7	Extended support	2.8.12 (*3.x available via SCL)
RHEL 8 / 9	Actively supported	3.11+ / 3.20+
Arch Linux	Rolling release	Latest (always 3.29 or newer)
Alpine	Lightweight distro	3.27.6 (as of 2025 edge)

I will create the PR for both C and C++, then release them.

[redboltz]

@theoparis I created PRs #1159, #1160 could you check them ?