ci: extend msys2 mingw CI (#3207)

* extend msys2 CI

- add 32-bit job
- add c++11/17 c++/interface tests copied from standard ci
- add numpy/scipy

* account for padding of PartialStruct in numpy dtypes test with mingw32

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci



* msys2 ci: add c++14 tests

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>