[release] pantsbuild.pants 1.28.0.dev2

[John Sirois]

The third weekly dev release in the 1.28.x series is now available on PyPI.

The release notes are available here: pantsbuild.org/notes-master.html

Thanks to this week's contributors:

     13 Eric Arellano
     11 John Sirois
      6 Stu Hood
      6 Asher Foa
      4 Benjy Weinberger
      1 Yi Cheng
      1 Danny McClanahan
      1 Daniel Wagner-Hall