executor_linux: Remove unreachable PATH= code (#9778)
executor_linux: Remove unreachable PATH= code (#9778)

This has to have been unused because the HasPrefix operation is
backwards, meaning a Command.Env that includes PATH= never would have
worked; the default path was always used.
dvusboy/nomad,hashicorp/nomad,burdandrei/nomad,burdandrei/nomad,dvusboy/nomad,burdandrei/nomad,dvusboy/nomad,burdandrei/nomad,dvusboy/nomad,dvusboy/nomad,hashicorp/nomad,dvusboy/nomad,burdandrei/nomad,hashicorp/nomad,hashicorp/nomad,burdandrei/nomad,hashicorp/nomad,hashicorp/nomad,burdandrei/nomad,dvusboy/nomad