[New cygwin version] cygwin-3.5.6

[github-actions]

Cygwin 3.5.6 release

https://github.com/cygwin/cygwin/releases/tag/cygwin-3.5.6

[dscho]

I opened an MSYS2 PR and corresponding Git for Windows PR. I still need to look into a particular required reactive change (an .isdevice() method was removed and we still need to understand the use case better in order to select what method to call instead, .isondisk() or .is_fs_special()).

[dscho]

/add relnote feature Comes with the MSYS2 runtime (Git for Windows flavor) based on Cygwin v3.5.6 (Git for Windows skipped v3.5.5 because it failed to pass Git's test suite).

The workflow run was started