bump atc
bump atc

[finishes #101461904]

Submodule src/github.com/concourse/atc ba635e4..a8d107c:
  > Increase size of started animation

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