[llvm] [Github][Bazel] Add Workflow to Run Bazel Build (PR #165071)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

We can't use custom runner images on the existing premerge infrastructure because we do not have a workaround for https://github.com/kubernetes-sigs/apiserver-network-proxy/issues/748 yet. That shouldn't be a permanent state, but is where we're at currently.

I don't think this is feasible to do on the free GIthub Actions runners.

https://github.com/llvm/llvm-project/pull/165071