Add mingw64 CI job

[quarckster]

mingw64 target is one of openssl primary supported platforms https://openssl-library.org/policies/general-supplemental/platforms/ but there is no job in the CI which test it.

Acceptance criteria

• New job mingw64 in windows.yml and in os-zoo.yml

[t8m]

We should move the cygwin build (which is not a primary platform and is slow) to OS Zoo and have a mingw64 job instead in windows-ci.yml on pull request.