HOTFIX remove protected_branches from asf.yaml

[mumrah]

The new parser seems not to support the null "~" thing. Instead, we'll just remove this section completely.

[chia7712]

The new parser seems not to support the null "~" thing

according to https://github.com/apache/infrastructure-asfyaml, it seems protected_branches: ~ is valid.

To completely remove all branch protection rules, set the protected_branches section to null:

github:
  protected_branches: ~

[mumrah]

We are using the "next gen" .asf.yaml parser which has had a few bugs. I think this (lack of support for ~) was one of them. I'm waiting to hear back from Infra if this change is needed or not. If you don't mind approving, I'll merge or close this PR depending on Infra's recommendation.

[chia7712]

I will unblock the merge :)

How can I monitor the infrastructure's response (or next gen parser)? thanks

[mumrah]

I've been chatting with them in #asfinfra https://infra.apache.org/slack.html