Delete cmake build github action (#509)
Delete cmake build github action (#509)

We've switched to using Kokoro. Some more discussion in #489, but the GitHub actions are limited in that we can't use very beefy or customized VMs and they can't talk to anything that requires secrets when they run on forks (so basically any kind of presubmit).
iree-org/iree,google/iree,iree-org/iree,google/iree,iree-org/iree,google/iree,google/iree,google/iree,google/iree,iree-org/iree,google/iree,iree-org/iree,iree-org/iree,iree-org/iree