[packaging] Explore compiling `libssh` statically

This would need to only concern wheels published to PyPI (manylinux et al.) The downstreams should still retain the ability to link against the OS-provided libs. Some research suggests that this is implementable though `extra_objects` and `-fPIC`: * https://cython-users.narkive.com/ocKNbCAj/wrap-c-static-library * https://groups.google.com/g/cython-users/c/gQQ1JUtckBE/m/hGb78MrNEGYJ * https://github.com/cython/cython/blob/404d958/Cython/Distutils/extension.py#L21 * https://github.com/cython/cython/blob/404d958/Cython/Debugger/Tests/TestLibCython.py#L138 * https://github.com/cython/cython/blob/404d958/Cython/Build/Dependencies.py#L151 * https://stackoverflow.com/a/2106051 * https://setuptools.pypa.io/en/latest/deprecated/distutils/setupscript.html#other-options * https://setuptools.pypa.io/en/latest/userguide/ext_modules.html#extension-api-reference