remove branch protection for repos governed by ee4j.jaxb-impl project
every PR in https://github.com/eclipse-ee4j/jaxb-istack-commons, https://github.com/lukasj/jaxb-fi, https://github.com/eclipse-ee4j/jaxb-stax-ex and https://github.com/eclipse-ee4j/jaxb-dtd-parser repos currently requires at least 1 approving review. Given number of active committers in these projects is low, this became an obstacle. I'd like to ask for removing this requirement on PRs there.