bump atc
bump atc

[finishes #97117996]

Submodule src/github.com/concourse/atc 03fc4b7..f843222:
  > specifying `get` and `put` in a step is not valid

CloudCredo/concourse,cjcjameson/concourse,cjcjameson/concourse,zachgersh/concourse,cjcjameson/concourse,concourse/concourse,longnguyen11288/concourse,CloudCredo/concourse,longnguyen11288/concourse,beni55/concourse,longnguyen11288/concourse,sedouard/concourse,concourse/concourse,beni55/concourse,squeedee/concourse,squeedee/concourse,beni55/concourse,concourse/concourse,sedouard/concourse,holgero/concourse,concourse/concourse,concourse/concourse,squeedee/concourse,zachgersh/concourse,holgero/concourse,holgero/concourse,CloudCredo/concourse,zachgersh/concourse,sedouard/concourse