[New msys2-runtime-package version] msys2-runtime: uname: add host machine tag to sysname

[github-actions]

msys2-runtime: uname: add host machine tag to sysname

This backports the `uname` patches from Cygwin where Windows/ARM64 is
indicated by an `-ARM64` suffix.

It corresponds to https://github.com/msys2/msys2-runtime/pull/245 and
https://github.com/msys2/msys2-runtime/pull/244.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

msys2/MSYS2-packages@7cfcfbe

[dscho]

This has been integrated via the rebase to v3.5.7.