bump atc
bump atc

[finishes #99063700]

Submodule src/github.com/concourse/atc efd2582..9772765:
  > remove all state from a build's delegate

Signed-off-by: Chris Walter <fe90a72e4e086d6063a97710fdb1d465540f326a@pivotal.io>

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