chore: remove nonexistent file from billing-v1's synth (#7073)
chore: remove nonexistent file from billing-v1's synth (#7073)


dazuma/google-cloud-ruby,dazuma/google-cloud-ruby,dazuma/google-cloud-ruby,dazuma/google-cloud-ruby,googleapis/google-cloud-ruby,googleapis/google-cloud-ruby,googleapis/google-cloud-ruby,googleapis/google-cloud-ruby,dazuma/google-cloud-ruby,googleapis/google-cloud-ruby,dazuma/google-cloud-ruby,googleapis/google-cloud-ruby