bump atc
bump atc

[finishes #108263400]

Submodule src/github.com/concourse/atc fe39d29..d8ed107:
  > Stop passing a PipelineDB into getbuild handler

zachgersh/concourse,cjcjameson/concourse,concourse/concourse,zachgersh/concourse,concourse/concourse,cjcjameson/concourse,concourse/concourse,longnguyen11288/concourse,zachgersh/concourse,longnguyen11288/concourse,longnguyen11288/concourse,concourse/concourse,cjcjameson/concourse,concourse/concourse