Fix: get_cross_building_settings for MSYS

[SSE4]

closes: #4315

Changelog: Fix: get_cross_building_settings for MSYS
Docs: Omit

@tags: slow, svn

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^{Note: By default this PR will skip the slower tests and will use a limited set of python versions. Check here how to increase the testing level by writing some tags in the current PR body text.}