[infra] Set up a bot to complain if an issue is not labelled with a package or type-infra

All (open) issues on this repo should have either a `package:...` or `type-infra` label.

We should set up a bot to complain if this is not the case.

A way to look at this manually:
https://github.com/search?q=repo%3Adart-lang%2Fnative+-label%3Apackage%3Affi+-label%3Apackage%3Affigen+-label%3Apackage%3Ajnigen+-label%3Apackage%3Anative_assets_cli+-label%3Apackage%3Anative_assets_builder+-label%3Apackage%3Anative_toolchain_c+-label%3Atype-infra+state%3Aopen&type=issues