Improve rest-api-spec test runner to fail tests that use headers but don't list them in the skip section #34650
Description
I'm raising this issue after submitting a pull request to add headers to the skip section of some tests that were missing it. I'm requesting that the Elasticsearch test runner fail tests that use features--specifically headers-- but don't include those features in the skip section.
I became aware of this issue when the Ruby client tests were failing against the latest rest-api-spec tests because some tests used headers but didn't specify features: headers in the skip section. The Ruby client doesn't support headers and wasn't able to properly skip these tests.