envPreInstall - sets ENV values for runners
common.setupPath - collects all Path operations into one function, runs before Ruby install
Add MSYS2 paths to all Windows builds for MSYS2 Bash use
External actions may use setup-ruby, and some actions make changes/additions to the build environment. These may be needed for dependencies.
Hence, allow those external actions to run code before 'bundle install'. This is done by passing a function as a parameter to setupRuby().
1. common.js - add function win2nix(path) to convert windows style paths to nix style
2. ruby_builder.js - use Git tar for windows-2016, leave windows-2019 as is