Pipelines should run for tags as well as branches

Use case seems common - we do all our work on branches, but we release tags... but pipelines does not run builds for tags.

So we have continuous delivery with tests running on everything except the actual deliverable

Obviously we don't release off broken branches, but there's still a chance something could go wrong while creating a tag. I'd rather have a confirmation build than just assume all is well.

I've raised a separate issue suggesting a feature to configure specific builds for tags vs. branches; but this one I'm raising as a bug as IMHO tags should be a build trigger.