[rubygems/rubygems] Remove unnecessary DIR constant
We have __dir__ which is the same thing.
__dir__
https://github.com/rubygems/rubygems/commit/f89776427f
[rubygems/rubygems] Remove unnecessary DIR constant
We have
__dir__which is the same thing.https://github.com/rubygems/rubygems/commit/f89776427f