[New msys2-runtime-package version] msys2-runtime: build for cygwin

[github-actions]

msys2-runtime: build for cygwin

In theory this means the "0001-Add-MSYS2-triplet.patch" patch
can be dropped.

msys2/MSYS2-packages@95fc0f0

[dscho]

This isn't critical for Git for Windows, we'll take this at our leisure with the next rebase to the next Cygwin version.