Use dockcross for wheel builds

See other discussion on !7058 (merged) for other changes.

The following discussion from !7058 (merged) should be addressed:

• @jcfr started a discussion: (+1 comment)

  dockcross/manylinux2010-x64

  Let's use the dockcross image, @thewtex and I are maintaining them and they are updated to always have the latest CMake, ninja with jobserver support,

  See https://github.com/dockcross/dockcross

Cc: @tjcorona